Question

Pulling of a cart or tram is an example of
A. Resultant force
B. Gravitational force
C. Contact force
D. Action at a distance force

Answer 1

As we know, pulling simple means to exert some force on a body which results in the movement of the body. Here, we will try to understand each force given in options and will check which force is responsible for the motion of a cart.

Complete answer:
Let us try to understand concepts of each force one by one and apply it to the motion of a cart.
Resultant force: In physics, a resultant force is the single force and associated torque obtained by combining a system of various forces acting on a body and which results in motion of a body in particular direction. But while pulling a cart only one force is applied by a puller for example say a horse who exert force on ground, resultant force is not responsible for motion of a cart.
Gravitational force: It’s the attraction force between two bodies but while pulling the cart we see, there is only one body which is actually moving, so gravitational force is not a reason for cart motion.
Contact force: It’s a force that acts at the point of contact between two objects. As the horse moves forwards it exerts a force on ground in backward direction this contact force helps in movement of cart in forward direction.So, Pulling of a cart is an example of Contact force.

Hence, the correct option is C.

Note: We must know that, Contact force works on the principle of Newton’s third law which states that for every action there is always equal and opposite reaction, which means while pulling a cart Force is exerted on ground in backward direction the motion of an object tends to in forward direction.