Question

Mr. Lake pushes a block of mass of 100kg with a force of 120N across a smooth surface. Mr. Earle pushes the same block in the opposite direction with an unknown force.

1) If the block accelerates at a rate of 0.7m/s^2, how much force was Mr. Earle pushing with? (Just give me the magnitude; don't worry about the direction)

2) If this block is pushed over a distance of 4m, how much work does Mr. Lake do on the box?

3) Using the same distance, how much work does Mr. Earle do on the block? (Recall that forces opposing the motion do NEGATIVE work!)

4) What is the net work done on the block?

5) If the block started at rest, how much kinetic energy does the block have after it is pushed?

6) How fast is the block traveling after the push?

7) Check this answer using kinematics! (The third kinematics equation would work well here...)

Answer 1