A horizontal constant force F pulls a block of mass m placed on a horizontal surface. If the coefficient of kinetic friction between the block and ground is `mu`, find the power delivered by the external agent after a time agent after a time t measured from the beginning of action of the force.

Explanation

To solve the problem, we need to find the power delivered by the external agent after a time \( t \) when a constant force \( F \) is applied to a block of mass \( m \) on a horizontal surface with a coefficient of kinetic friction \( \mu \).

### Step-by-Step Solution:

1. **Identify Forces Acting on the Block**:
- The gravitational force acting downwards: \( mg \)
- The normal force acting upwards: \( N = mg \)
- The applied force \( F \) acting horizontally to the right.
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