Question

Movers push an 80 kg trunk at 1.0 m/s when they encounter a 2.5 m long stretch of floor where the coefficient of kinetic friction is 0.30. During this stretch of floor, the movers push the trunk with a steady force of 220 N.

a. Determine the net force along the direction of motion

b. Determine the net work done on the trunk

c. Using the work-energy theorem, determine the speed of the trunk at the end of the 2.5 m stretch.

Please show your work clearly and write step by step solution including numeric substitutions and etc. To make it easier, please do this in paper and include the pictures. thanks

Answer 1

To solve this problem you have to know about work and kinetic energy

Step 1.

Definition:

Work: In the field of physics we do not just talk about work, but mechanical work and reportedly does work when a force moves its point of application in the same direction. Mechanical work can be designated with the letter T or W.

When a heavy object against gravity gets up work is done. The heavier the object, or the higher you rise, the greater the work. In all cases where work is done involves two factors: the application of a force and movement of an object, due to the action of said force.

Kinetic energy: is the energy that has due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to the speed displayed.

Step 2.

a. Determine the net force along the direction of motion

First we need know the forces that act in the system

where the normal is equal to the weight

The forces that act in the direction of motion are the forces that the movers do it and the force by friction

b. Determine the net work done on the trunk

The work you can calculate how as the product of net force by the distance

c. Using the work-energy theorem, determine the speed of the trunk at the end of the 2.5 m stretch

This theorem says: The work done by the net force on a particle equals the change in kinetic energy of the particle.

where K_f is the final kinetic energy and K_o is initial kinetic energy

If you have any question please let me know in the comments