I don't know where to start solving this question. Please help!

A 320 kg piano slides 3.7 m down a 32 degree incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. The effective coefficient of kinetic friction is 0.39. Calculate the force exerted by the man. Calculate the work done by the man on the piano. Calculate the work done by the friction force.

To solve this question, we can break it down into several steps.

Step 1: Calculate the gravitational force acting on the piano.
The force due to gravity can be calculated using the formula F = m * g, where m is the mass of the piano and g is the acceleration due to gravity. In this case, the mass of the piano is 320 kg, and the acceleration due to gravity is approximately 9.8 m/s^2. Therefore, the gravitational force on the piano is F = 320 kg * 9.8 m/s^2.

Step 2: Resolve the force due to gravity into its components.
Since the piano is sliding down an inclined plane, we need to consider the force of gravity in both the vertical and horizontal directions. The vertical component is acting perpendicular to the incline and does not affect the motion of the piano along the incline. The horizontal component of the gravitational force is parallel to the incline and opposes the motion of the piano.

Step 3: Calculate the force exerted by the man.
The force exerted by the man is the force required to keep the piano from accelerating down the incline. It is equal in magnitude and opposite in direction to the horizontal component of the gravitational force acting on the piano. To calculate this force, we need to determine the horizontal component of the gravitational force using trigonometry.

Step 4: Calculate the work done by the man on the piano.
Work can be calculated using the formula W = F * d * cos(theta), where F is the force, d is the distance, and theta is the angle between the force and the displacement. In this case, the force is the force exerted by the man, the distance is the distance the piano slides down the incline, and the angle theta is 180 degrees since the force and displacement are in opposite directions.

Step 5: Calculate the work done by the friction force.
The work done by the friction force can be calculated using the formula W = F * d, where F is the force of friction and d is the distance the piano slides down the incline. In this case, the force of friction can be calculated using the formula F = coefficient of friction * normal force, where the normal force is the vertical component of the gravitational force.

By following these steps, you should be able to solve the question.