1. Work Done

* Definition: Work is done when a force causes an object to move a certain distance.

* Formula: Work (W) = Force (F) x Distance (d)

In this case:

* Force (F) = 225 N

* Distance (d) = 6 m

Therefore, the work done:

* W = 225 N * 6 m = 1350 J (Joules)

2. Thermal Energy Due to Friction

* Concept: Since the crate moves at a constant velocity, the applied force is equal and opposite to the force of friction. This means the work done against friction is equal to the work done by the applied force.

* Conversion: 1 calorie (cal) = 4.184 Joules (J)

Therefore:

* Thermal energy produced by friction = 1350 J * (1 cal / 4.184 J) = 322.5 cal (approximately)

Answer:

* The work required to push the crate is 1350 Joules.

* The thermal energy produced by friction is approximately 322.5 calories.