Question

A block, initially at rest, feels a constant net force of 75 N for a distance of 0.60 m along the floor. Ignore friction. A.) what is the final kinetic energy of the block? B.) if the block has a mass of 0.020 kg what is its final speed?

Answer 1

Given:

A block, initially at rest, feels a constant net force of 75 N for a distance of 0.60 m along the floor. Ignore friction. A.) what is the final kinetic energy of the block? B.) if the block has a mass of 0.020 kg what is its final speed?

From conservation of energy , the work done on the block is equal to the change in kinetic energy :

A.)   ===> But , the initial kinetic energy is

. We thus have the final kinetic energy is :

  --- SOLUTION .

B.) If the mass is   , we can compute the final speed :

  ===>

===>

===> The final speed is :

   --- SOLUTION .