A man pushes against a rigid, immovable wall. Which of the following is the most accurate statement concerning this situation?
A) The man can never exert a force on the wall which exceeds his weight.
B) If the man pushes on the wall with a force of 200 N, we can be sure that the wall is pushing back with a force of exactly 200 N on him.
C) Since the wall cannot move, it cannot exert any force on the man.
D) The man cannot be in equilibrium since he is exerting a net force on the wall.
E) The friction force on the man's feet is directed to the left.
Question 2
A very long nonconducting cylinder of diameter 10.0 cm carries charge distributed uniformly over its surface. Each meter of length carries +5.50 C of charge.
A proton is released from rest just outside the surface. How far will it be from the SURFACE of the cylinder when its speed has reached 2550 km/s? (k = 1/40 = 8.99 109 N m2/C2, e = 1.60 10-19 C, mproton = 1.67 x 10-27 kg)