Question

What is an inclined plane? Give two examples where it is used to raise load with less effort.

Answer 1

Hint: In order to solve this question we need to understand the force and the work. So force is defined as the push or pull on a body which changes state of motion, for example if it is at rest then force applied could bind it to move and thereby changing state and vice versa. Newton's second law force is defined mathematically as the rate of change of linear momentum. Work is defined as the energy that is stored in the body and it is equal to applied force causing unit displacement of the body. So we need to minimize work done and this is done if the body has a circular shape or it is placed on something which can be easily moved.

Complete step by step answer:
Inclined plane is defined as a plane which is inclined to some angle with the ground hence making a simple sloping surface. It is used to lift heavy objects. Inclined plane looks like this as shown in diagram,

Actually if we consider a heavy mass say mass “m” then force needed to lift the body up is given by, $F = mg$ and this is force which one needs to overcome gravitational force of attraction.

Now consider an inclined plane, inclined to some angle, say $\theta $. Then the force required to move up the incline is, $F = mg\sin \theta $ and this is in comparison less than the force that needed to vertically lift up the body, hence in this way inclined plane uses less effort to raise.

Examples where it is used to raise load with less effort are:
-Most common are the railway bridges over the railway tracks that help the persons to cross with less effort.
-And the next is when we unload any product from truck or heavy vehicle onto the roads then we use an inclined plane so that it would be much easier to bring it down to roads.

Note: It should be remembered that we define the forces above in absence of frictional force, but instead if frictional force is present on the inclined plane we still need to do less work in lifting up the body. Also energy is always conserved during lifting up because when we start lifting then we store kinetic energy in it and after some time when it has some height it stores potential energy.