Understanding the Concepts

* Work: Work is done when a force causes an object to move a certain distance. It's calculated as: Work (W) = Force (F) × Distance (d)

* Constant Speed: If an object moves at a constant speed, the net force acting on it is zero. This means the applied force is equal and opposite to the force of gravity.

Calculations

1. Identify the forces:

* The applied force is lifting the block.

* The force of gravity is pulling the block down (this is the weight of the block, 15 Newtons).

2. Since the block moves at constant speed, the applied force is equal to the weight of the block (15 N).

3. Calculate the work:

* Work (W) = Force (F) × Distance (d)

* W = 15 N × 3.0 m

* W = 45 Joules (J)

Answer: The applied force does 45 Joules of work to lift the block.