A. 45 - 13 = 32 Newtons
B. Work done = 32 * 4 = 128 Newton meters or JOULES
C. -128 Joules total but the friction will do 13* 4 = 52 Joules so you need to absorb 128 - 52 if you stop it in 4 meters. Question C is not clear.
A 20.0 kg block is being pushed forward on a flat surface with a force of magnitude 45.0 N against a frictional force of 13.0 N.
A. What is the net force acting on the block?
B. What is the change in kinetic energy after the force has pushed the block for 4.0 m?
C. How much work would it take to stop the block?
1 answer
1 answer