An astronaut standing on the surface of Ceres, the largest asteroid, drops a rock from a height of 10m. It takes 8.06s to hit the ground.

___	Calculate the acceleration of gravity on Ceres.
___	Calculate the gravitational acceleration 50km from the surface of Ceres
___	Find the mass of Ceres, given the radius is 510km.

1.	-0.308
2.	1.2*1021
3.	-0.26
4.	8.17*109
5.	-32.016

Olympic ice skaters are able to spin at about 5rev/s.

What is the centripetal acceleration of the skater's nose if it is 0.12m from the axis of rotation?
___	An exceptional skater named Dick Button was able to spin much faster in the 1950s than anyone since - at about 9rev/s. What was the centripetal acceleration of the tip of his nose, assuming it is at 0.12m radius?
____	What is their angular velocity in radians per second?

1.	31.42
2.	118.44
3.	383.73

Two disgruntle business people are trying to using a revolving door, as shown. The woman on the left exerts s force of 602N perpendicular to the door and 1.50m from the hub's center, while the man on the right exerts a force of 822N perpendicular to the door and 0.93m from the hub's center. Find the net torque on the revolving door.

When opening a door, you push on it perpendicularly with a force of 53.40N at a distance of 0.78m from the hinges. What torque are you exerting relative to the hinges?

A runner taking part in the 200m dash must run around the end of a track that has a circular arc with a radius of curvature of 30m. If he complete the 200m dash in 23.2s and runs at a constant speed throughout the race, what is the magnitude of centripetal acceleration as he runs the curved portion of the track?

Zorch, an archenemy of Superman, decides to slow Earth's rotation to once per 28h by exerting an opposing force at and parallel to the equator. Superman is not immediately concerned because he knows Zorch can only exert a force of 4E7N. How long must Zorch push with this force to accomplish his goal? Useful information: M_earth = 6*10²⁴kg, R_earth = 6400km, Earth is a solid sphere. Your answer will be on the order of 10^₁₈s. Enter the coefficient and no units.

Suppose a 900kg car is on the bridge shown below with its center of mass halfway between the hinges and the cable attachments. Find the force in T if the mass of the bridge is 2500kg.

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