An astronaut is in orbit around the earth. The feeling of weightlessness that he experiences is due to the absence of which force?

Mass of Mars:

Universal gravitation constant:

Radius of Mars:

A buggy on the surface of Mars locks up it's break and slides on Martian ice. If the buggy was traveling at and took to stop. Determine the coefficient of friction between Martian ice and the tires.

Suppose that a student pushes his physics textbook across the table with his hand. In doing so, what type of force is acting on the book?

Nicola is attempting to create a single tiered mobile as shown. She has a wooden dowel (, ), and two distinct bird ornaments (, ) which she wishes to attach on either end of the dowel.

If Nicola places ornament , to the left of the dowel's midpoint, and ornament , to the right of the dowel's midpoint, where should she attach the mobile string in order for it to balance?

Note: figure not drawn to scale.

A spring is attached to the top of a box. The constant of the spring is and a block of mass attached to the other end. If the spring is initially compressed past equilibrium, at what rate is the box initially accelerating? Is the initial acceleration up or down?

Consider the following scenario:

If the force of tension is , the coefficient of static friction is , and the angle measures , what is the maximum mass of the block that will result in motionlessness?

An adventurous teenager has decided to pick up skydiving. If the teen has a mass of , a reference area of , and a terminal velocity of , what is the density of the air through which the diver is traveling?

A car travels around a circular racetrack at a velocity of . The radial distance between the center of the racetrack and the center of the car at any given point of its trip is . What is the centripetal force on the car?

A scuba diver and his equipment have a total mass of and a total volume of . If he wants to maintain a constant depth of , what average vertical force must he exert on the water with his flippers?

Consider a sphere with a radius. What weight would a scale read if the sphere was halfway submerged in water? Take the density of water to be(A picture will help).