A lighter block (2 kg) and a heavier block (8 kg) sit on a frictionless surface. Both blocks are initially at rest. The same force of 4 N then pushes to the right on each block for a distance of 9 m. What are the changes in kinetic energy of the blocks? What are the final kinetic energies of the blocks?What are the final momenta of the blocks?What are the changes in momenta of the blocks? How long does it take each block to travel the distance of 9 m?

1 answer

a) W = Fd That's the change in KE
b) Same thing
c) Now you must find the final velocities. KE = 1/2mv^2, solve for v
momentum = mv
d) momentum is always conserved
e) a = F/m, v = at, solve for t