Question

In which direction does a car at rest move when pushed by a few persons?
A) In the direction opposite to push.
B) In the direction of the push.
C) Making an acute angle with the push.
D) None of the above.

Answer 1

Hint: An external effort that is in the form of a push or pulls which moves or tries to move a body at rest; stop or tries to stop a body in motion; changes or tries to change the direction of motion of a body is called as Force.

Complete step by step solution:
The physical quantity that changes or tries to change the state of rest or uniform motion of a body along a straight line is called Force. Force will not act in the direction of motion. Depending on the situation, force may be along, opposite to, normal to or may make some other angle with. In every case, it is parallel to the acceleration.
Here in the question, a car which is at rest and when pushed by a few persons it starts moving. And its direction is along the direction of the push.
Other than this push few forces are acting on the car. They are frictional force, gravitational force.
That is, the frictional force is acting opposite to the applied force and the weight of the car is acting downwards due to gravity.
By observing these facts, we can say that the car is moving along the direction of the push and the remaining options are wrong for this case.

The correct option is (B).

Note:
According to Newton’s second law of motion, which states that the rate of change of momentum of a body is directly proportional to the net external force acting on the body and takes place in the direction in which the force acts.
Force is a vector quantity, which has both magnitudes as well as direction.