A grasshopper of mass 0.12 g jumps vertically. It uses its back legs over a time of 0.020s to jump, leaving the ground with a velocity of 3.0 ms.
What is the average power developed by the legs of the grasshopper?
A 9.0 x 10-'W
B
1.8 x 10-2W
с
2.7 x 10-2W
D 37 W

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. her friend, a hockey player, then shoots a hockey puck at each shoe. the first puck immediately comes to rest after it collides with the left shoe. the second puck rebounds after it collides with the right shoe. if each hockey puck has the same incoming speed, which shoe has greater speed after the collision? the right shoe. both shoes have the same speed. the left shoe.

Given the position vector of the particle r(t)=(t+1)i+(t^2−1)j+2t k, find the particle's velocity and acceleration vectors at t=1

The field between two charged parallel plates is kept constant. if the two plates are brought closer together, the potential difference between the two plates either a) decrease b) does not change c) increase?