Two protons, each of charge 1.60 10-19 C, are 3.00 10-5 m apart. What is the change in potential energy if they are brought 1.00 10-5 m closer together? (ke = 8.99 109 Nm2/C2)
a. 3.84 10-24 J
c. 1.15 10-23 J
b. 3.20 10-16 J
d. 3.20 10-19 J
Question 2
A 20-g bullet moving at 1000 m/s is fired through a one-kg block of wood emerging at a speed of 200 m/s. What is the change in the kinetic energy of the bullet-block system as a result of the collision assuming the block is free to move?
a. 0 J
c. 9.5 kJ
b. -9.5 kJ
d. -18 J