The angle of inclination of an inclined plane is 60 degrees and the coefficient of friction between a 10kg body and its surface is 0.2. We need to determine the acceleration of the body down the plane in m/s.

To solve this problem, we can follow these steps:

1. Identify the forces acting on the body:
- Weight (mg): The force due to gravity acting vertically downward. Its magnitude can be calculated using the formula: Weight = mass × acceleration due to gravity = 10 kg × 9.8 m/s^2 = 98 N.
- Normal force (N): The force exerted by the inclined plane perpendicular to its surface. It is equal in magnitude and opposite in direction to the component of the weight acting perpendicular to the plane. In this case, N = mg cosθ = 10 kg × 9.8 m/s^2 × cos(60°) = 49 N.
- Friction force (f): The force opposing the motion of the body along the inclined plane. Its magnitude can be calculated using the formula: f = coefficient of friction × N = 0.2 × 49 N = 9.8 N.

2. Resolve the weight force into its components:
- Parallel to the inclined plane (mg sinθ): This component of the weight force acts down the plane and contributes to the body's acceleration.
- Perpendicular to the inclined plane (mg cosθ): This component of the weight force is balanced by the normal force.

3. Calculate the net force acting on the body:
- Net force (Fnet) = Parallel component of weight force - Friction force = mg sinθ - f = 10 kg × 9.8 m/s^2 × sin(60°) - 9.8 N = 49 N - 9.8 N = 39.2 N.

4. Apply Newton's second law of motion:
- Fnet = mass × acceleration
- Plugging in the values, we have 39.2 N = 10 kg × acceleration.
- Solving for acceleration gives us: acceleration = 39.2 N / 10 kg = 3.92 m/s^2.

Therefore, the acceleration of the body down the inclined plane is 3.92 m/s^2.

A = (5√3 -1 )m/s