Question

A 5kg object slides down a frictionless surface inclined at an angle of 30º from the horizontal. The total distance moved by the object along the plane is 10 meters. The work done on the object by the normal force of the surface is? The answer is zero. They they that the angle is 90degrees?? But it says 30 degrees! where do they get cos(90) from? me I get cos(30)

Answer 1

The work done on the object by the normal force of the surface is zero because the normal force and the displacement are perpendicular to each other.

Step-by-step explanation:

The work done on the object by the normal force of the surface is indeed zero. This is because the normal force and the displacement of the object are perpendicular to each other. In this case, the angle between the surface and the horizontal is 30 degrees. The work done is given by the formula:

Work = Force x Distance x cos(angle)

Since the normal force is perpendicular to the displacement, the angle between them is 90 degrees. So, cos(90) = 0. Therefore, the work done by the normal force is zero.