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?
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