Introductory Principles - High School Physics
Card 0 of 20
Michael's scale measures the mass of objects as consistently 
less than their actual mass. How would you describe the scale?
Michael's scale measures the mass of objects as consistently
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS 
short. Even though it displays the wrong value, it is consistent. That means it is precise. Measuring a 
object will always display a mass of 
; the results are easily reproduced.
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by 
.
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by
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Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
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An brand of fruit snacks claims that each bag of fruit snacks has a mass of 
. After weighing three bags, Wally observes the masses to be 
, 
, and 
.
How can Wally describe the accuracy and precision of the first bag he measured?
An brand of fruit snacks claims that each bag of fruit snacks has a mass of
How can Wally describe the accuracy and precision of the first bag he measured?
The claim for the mass of the first bag is accurate; the brand says there should be 
in each bag and there was 
in the first bag.
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to 
.
The claim for the mass of the first bag is accurate; the brand says there should be
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to
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A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
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Which of these is an example of high accuracy?
Which of these is an example of high accuracy?
Accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
In contrast, precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
In contrast, precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
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Which of these is an example of high precision?
Which of these is an example of high precision?
Precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
In contrast, accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
In contrast, accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
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A scientist measures how far a particle travels within a given amount of time. Every second she measures how far it has gone, and creates a graph of her results. What is the independent variable in this experiment?
A scientist measures how far a particle travels within a given amount of time. Every second she measures how far it has gone, and creates a graph of her results. What is the independent variable in this experiment?
An independent variable is manipulated by the experimenter. Any changes made are predictable. The dependent variable reacts to changes made to the independent variable. Its changes are not controlled by the experimenter and can be hard to predict.
In this particular experiment, the scientist is measuring how the particle's distance changes over a given time. She is able to control the amount of time that she measures, but is only able to observe the distance traveled.
In the graph, the independent variable will be graphed on the x-axis.
An independent variable is manipulated by the experimenter. Any changes made are predictable. The dependent variable reacts to changes made to the independent variable. Its changes are not controlled by the experimenter and can be hard to predict.
In this particular experiment, the scientist is measuring how the particle's distance changes over a given time. She is able to control the amount of time that she measures, but is only able to observe the distance traveled.
In the graph, the independent variable will be graphed on the x-axis.
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When looking at velocity in terms of distance and time, what is the independent variable?
When looking at velocity in terms of distance and time, what is the independent variable?
There are a few ways to think of this question. The first is to imagine you are graphing velocity. Since the equation is 
, the displacement would be on the y-axis and time would be on the x-axis. The x-axis is going to be where we put our independent variable.
The other way to think of this is to ask yourself what our "inputs" and "outputs" would be if we were measuring velocity. Imagine you're walking down the street and you record how far you travel every second. The time is what you are "inputting" and your distance travelled is your "output."
There are a few ways to think of this question. The first is to imagine you are graphing velocity. Since the equation is
The other way to think of this is to ask yourself what our "inputs" and "outputs" would be if we were measuring velocity. Imagine you're walking down the street and you record how far you travel every second. The time is what you are "inputting" and your distance travelled is your "output."
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You are looking at a graph of the motion of a vehicle. On the y-axis is displacement and on the x-axis is time. Which of the following is the independent variable?
You are looking at a graph of the motion of a vehicle. On the y-axis is displacement and on the x-axis is time. Which of the following is the independent variable?
Independent variables are predetermined by the experimenter and can be manipulated to change the measured dependent variable. Independent variables are generally graphed on the x-axis, while dependent variables are generally graphed on the y-axis.
In this question, time is the independent variable and displacement is the dependent variable. The experimenter can select sampling times, but cannot necessarily predict the displacement that will be measured at each point. This defines time as the independent variable.
Independent variables are predetermined by the experimenter and can be manipulated to change the measured dependent variable. Independent variables are generally graphed on the x-axis, while dependent variables are generally graphed on the y-axis.
In this question, time is the independent variable and displacement is the dependent variable. The experimenter can select sampling times, but cannot necessarily predict the displacement that will be measured at each point. This defines time as the independent variable.
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Where is the independent variable most commonly displayed on a graph?
Where is the independent variable most commonly displayed on a graph?
The independent variable is controlled by the experimenter, while the dependent variable will fluctuate based on independent variable inputs. The independent variable is always displayed on the x-axis of a graph, while the dependent variable appears on the y-axis. Time is a common independent variable, as it will not be affeced by any dependent environemental inputs. Time can be treated as a controllable constant against which changes in a system can be measured.
The independent variable is controlled by the experimenter, while the dependent variable will fluctuate based on independent variable inputs. The independent variable is always displayed on the x-axis of a graph, while the dependent variable appears on the y-axis. Time is a common independent variable, as it will not be affeced by any dependent environemental inputs. Time can be treated as a controllable constant against which changes in a system can be measured.
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Which of the following is a vector quantity?
Which of the following is a vector quantity?
A vector has both magnitude and direction, while a scalar has only magnitude. Ask yourself, "for which of these things is there a direction?" For displacement, we would say "50 meters NORTH," whereas with the others, we would say "50 meters," "20 seconds," or "30 miles per hour."
Important distinctions to know:
Speed is a scalar, while velocity is a vector.
Distance is a scalar, while displacement is a vector.
Force and acceleration are vectors. Time is a scalar.
A vector has both magnitude and direction, while a scalar has only magnitude. Ask yourself, "for which of these things is there a direction?" For displacement, we would say "50 meters NORTH," whereas with the others, we would say "50 meters," "20 seconds," or "30 miles per hour."
Important distinctions to know:
Speed is a scalar, while velocity is a vector.
Distance is a scalar, while displacement is a vector.
Force and acceleration are vectors. Time is a scalar.
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Which of the following is a scalar quantity?
Which of the following is a scalar quantity?
The difference between a scalar and a vector is that a vector requires a direction. Scalar quantities have only magnitude; vector quantities have both magnitude and direction. Time is completely separated from direction; it is a scalar. It has only magnitude, no direction.
Force, displacement, and acceleration all occur with a designated direction.
Important distinctions to know:
Speed is a scalar, while velocity is a vector.
Distance is a scalar, while displacement is a vector.
Force and acceleration are vectors. Time is a scalar.
The difference between a scalar and a vector is that a vector requires a direction. Scalar quantities have only magnitude; vector quantities have both magnitude and direction. Time is completely separated from direction; it is a scalar. It has only magnitude, no direction.
Force, displacement, and acceleration all occur with a designated direction.
Important distinctions to know:
Speed is a scalar, while velocity is a vector.
Distance is a scalar, while displacement is a vector.
Force and acceleration are vectors. Time is a scalar.
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Michael walks 
north, 
west, 
south, 
east, and then stops to catch his breath. What is the magnitude of his displacement from his original point?
Michael walks
Displacement is a vector quantity; the direction that Michael travels will be either positive or negative along an axis. We are being asked to solve for his position relative to his starting point, NOT for the distance he has walked.
First we need to find his total distance travelled along the y-axis. Let's say that all of his movement north is positive and south is negative.
. He moved a net of 5 meters to the north along the y-axis.
Now let's do the same for the x-axis, using positive for east and negative for west.
. He moved a net of 9 meters to the east.
Now to find the resultant displacement, we use the Pythagorean Theorem. The net movement north will be perpendicular to the net movement east, forming a right triangle. Michael's position relative to his starting point will be the hypotenuse of this triangle.
Now take the square root of both sides.
Since the problem only asks for the magnitude of the displacement, we do not need to provide the direction.
Displacement is a vector quantity; the direction that Michael travels will be either positive or negative along an axis. We are being asked to solve for his position relative to his starting point, NOT for the distance he has walked.
First we need to find his total distance travelled along the y-axis. Let's say that all of his movement north is positive and south is negative.
Now let's do the same for the x-axis, using positive for east and negative for west.
Now to find the resultant displacement, we use the Pythagorean Theorem. The net movement north will be perpendicular to the net movement east, forming a right triangle. Michael's position relative to his starting point will be the hypotenuse of this triangle.
Now take the square root of both sides.
Since the problem only asks for the magnitude of the displacement, we do not need to provide the direction.
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Leslie walks 
north, 
east, 
north, and then 
west before stopping. What is her displacement from her original location?
Leslie walks
Displacement is a vector quantity; it will have both magnitude and direction.
First we need to find his total distance travelled along the y-axis. Let's say that all of her movement north is positive and south is negative.
. She moved a net of 30 meters to the north.
Now let's do the same for the x-axis, using positive for east and negative for west.
. She moved a net of 29 meters to the east.
Now, to find the resultant displacement, we use the Pythagorean Theorem. Her net movement north will be perpendicular to her net movement east, forming a right triangle. Her location relative to her starting point will be the hypotenuse of the triangle.
Now take the square root of both sides.
Since we are solving for a vector, we also need to find the direction of this distance. We do this by solving for the angle of displacement.
To find the angle, we use the arctan of our directional displacements in the x- and y-axes. The tangent of the angle will be equal to the x-displacement over the y-displacement.
Combining the magnitude and direction of our distance gives us the displacement: 
.
Displacement is a vector quantity; it will have both magnitude and direction.
First we need to find his total distance travelled along the y-axis. Let's say that all of her movement north is positive and south is negative.
Now let's do the same for the x-axis, using positive for east and negative for west.
Now, to find the resultant displacement, we use the Pythagorean Theorem. Her net movement north will be perpendicular to her net movement east, forming a right triangle. Her location relative to her starting point will be the hypotenuse of the triangle.
Now take the square root of both sides.
Since we are solving for a vector, we also need to find the direction of this distance. We do this by solving for the angle of displacement.
To find the angle, we use the arctan of our directional displacements in the x- and y-axes. The tangent of the angle will be equal to the x-displacement over the y-displacement.
Combining the magnitude and direction of our distance gives us the displacement:
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Angie runs around a circular track for 
. The track is 
and she runs at a rate of 
. What is her total displacement?
Angie runs around a circular track for
Since she is running on a circular track, every time she makes a loop she has a total displacement of 
. Remember, displacement take into account how far you've travelled, it only uses the total change in distance from where you start and where you stop. Using dimensional analysis, we can determine how many laps she runs in 20 minutes.
After twenty minutes, she has made EXACTLY two loops around the track. That means she is starting and stopping in EXACTLY the same place. Her displacement would be 
, since there is no change between her starting position and her ending position.
Since she is running on a circular track, every time she makes a loop she has a total displacement of
After twenty minutes, she has made EXACTLY two loops around the track. That means she is starting and stopping in EXACTLY the same place. Her displacement would be
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Walter is washing windows on a large building. He starts by washing the window on the 4th floor. He then moves down to the 3rd floor, then up to the 6th floor, then down to the 5th floor, then down to the 2nd floor, and finally he washes the 1st floor window. What is his total displacement?
Walter is washing windows on a large building. He starts by washing the window on the 4th floor. He then moves down to the 3rd floor, then up to the 6th floor, then down to the 5th floor, then down to the 2nd floor, and finally he washes the 1st floor window. What is his total displacement?
Displacement is a vector relating the starting position to the ending position. Displacement does not take into account the route to arrive at the endpoint, and has both magnitude and direction.
In spite of taking a very complicated route to get there, Walter starts at the 4th floor and ends at the 1st floor.
Sine the result is negative, the displacement is 3 floors downward.
Displacement is a vector relating the starting position to the ending position. Displacement does not take into account the route to arrive at the endpoint, and has both magnitude and direction.
In spite of taking a very complicated route to get there, Walter starts at the 4th floor and ends at the 1st floor.
Sine the result is negative, the displacement is 3 floors downward.
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Walter is washing windows on a large building. He starts by washing the window on the 4th floor, then down to the 3rd floor, then up to the 6th floor, then down to the 5th floor, then down to the 2nd floor, and finally he washes the 1st floor window. What is his total distance?
Walter is washing windows on a large building. He starts by washing the window on the 4th floor, then down to the 3rd floor, then up to the 6th floor, then down to the 5th floor, then down to the 2nd floor, and finally he washes the 1st floor window. What is his total distance?
Distance is a scalar quantity and will take into account only the number of floors travelled, regardless of the direction of movement.
Walter takes an incredibly complicated path to wash the windows on the building. When calculating distance, we add up all the movement he does, regardless of direction.
First, he travels down one floor (4th to 3rd).
Then he travels up three floors (3rd to 6th).
Then he travels down one floor (6th to 5th), then down another three floors (5th to 2nd).
Finally, he travels down one more floor (2nd to 1st).
In total, Walter travelled 
.
Distance is a scalar quantity and will take into account only the number of floors travelled, regardless of the direction of movement.
Walter takes an incredibly complicated path to wash the windows on the building. When calculating distance, we add up all the movement he does, regardless of direction.
First, he travels down one floor (4th to 3rd).
Then he travels up three floors (3rd to 6th).
Then he travels down one floor (6th to 5th), then down another three floors (5th to 2nd).
Finally, he travels down one more floor (2nd to 1st).
In total, Walter travelled
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Ariel walks 
to the east, 
to the west, and then 
to the east again. What is her total displacement?
Ariel walks
Displacement is a vector quantity, with both magnitude and direction. Remember, displacement does not take into account the route traveled, only the difference between starting position and ending position.
All movement in this question occurs along the x-axis (east and west. We use positive for east and negative for west, since direction is important to measure displacement.
This means that her total displacement was 
.
Displacement is a vector quantity, with both magnitude and direction. Remember, displacement does not take into account the route traveled, only the difference between starting position and ending position.
All movement in this question occurs along the x-axis (east and west. We use positive for east and negative for west, since direction is important to measure displacement.
This means that her total displacement was
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Which of these is a vector quantity?
Which of these is a vector quantity?
Scalar quantities give a magnitude, while vector quantities give a magnitude and a direction. The answer will be a measurement that must act in a given direction.
Distance is a measure of length, regardless of the direction. Displacement is the vector equivalent of distance.
Speed is a measure of rate, regardless of direction. Velocity is the vector equivalent of speed.
Temperature and time do not act in any direction and are purely scalar.
Acceleration must act in a given direction, and is a vector. An acceleration is described by both a magnitude and a direction of action.
Scalar quantities give a magnitude, while vector quantities give a magnitude and a direction. The answer will be a measurement that must act in a given direction.
Distance is a measure of length, regardless of the direction. Displacement is the vector equivalent of distance.
Speed is a measure of rate, regardless of direction. Velocity is the vector equivalent of speed.
Temperature and time do not act in any direction and are purely scalar.
Acceleration must act in a given direction, and is a vector. An acceleration is described by both a magnitude and a direction of action.
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Which of these is a scalar quantity?
Which of these is a scalar quantity?
Scalar quantities give a magnitude, while vector quantities give a magnitude and a direction. The answer will be a measurement that does not change, regardless of the direction of action.
Displacement is a measure of length in a given direction; distance is the scalar version of displacement.
Velocity is a measure of rate in a given direction; speed is the scalar version of velocity.
Force is a derivative of acceleration, and can only act in a given direction. There is no scalar equivalent of force. Similarly, momentum is a derivative of velocity and has no scalar equivalent.
Mass is a measure solely of magnitude, and requires no direction of action. Mass is a scalar quantity.
Scalar quantities give a magnitude, while vector quantities give a magnitude and a direction. The answer will be a measurement that does not change, regardless of the direction of action.
Displacement is a measure of length in a given direction; distance is the scalar version of displacement.
Velocity is a measure of rate in a given direction; speed is the scalar version of velocity.
Force is a derivative of acceleration, and can only act in a given direction. There is no scalar equivalent of force. Similarly, momentum is a derivative of velocity and has no scalar equivalent.
Mass is a measure solely of magnitude, and requires no direction of action. Mass is a scalar quantity.
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