In which of the following situations is your body closest to being in equilibrium?

In which of the following situations is your body closest to being in equilibrium?

a. Running at constant speed in a circle.

b. While jumping straight up.

c. While hitting a stone wall.

d. Running at constant speed in a straight line.

e. At the highest point of a vertical hop.

2 Suppose that it takes an average force of 2000 Newtons to draw a catapult back by two meters. How much potential energy

is stored in the drawn catapult?

a. 2000J.

b. 200J.

c. 0J.

d. 4000J.

e. 400J.

3 A man is trying to push a railroad car along a level track. He is able to exert a horizontal force of about 1000N and the

friction force is negligible. If the mass of the railroad car is 100 metric tons or 100; 000kg, it will accelerate along the track

at

a. 0:009m/s2.

b. 90m/s2.

c. 100m/s2.

d. 0m/s2.

e. 0:01m/s2.