Newton First Law of Motion

All the facts taken from Galileo law of inertia or Newton’s first law of motion. The ideas suggested by Galileo and were formulated into law by Newton. Newton’s First law: “a body at rest will remain at rest and a body in motion will remain in uniform motion unless acted upon by an unbalanced force.” This law is also known as law of inertia. It gives quantitative definition of force.

This means that all objects resist in changing their state. This state can be changed only by applying some unbalanced external force.. From Newton's First Law motion we can predict the behaviour of an object. If a ball is lying on the table, it will not start rolling or fall off the table unless a force acts upon it to cause it to do so. Moving objects don't change their direction unless a force causes them to move from their path.

There are two conditions on which the first law of motion is dependent :

1. Objects at rest: When an object is at rest velocity (v = 0) and acceleration (a = 0) are zero.Therefore, the object continues to be at rest.

2. Objects in motion : When an object is in motion, velocity is not equal to zero while acceleration is equal to zero. Therefore, the object will continue to be in motion with constant velocity and in the same direction.

Here are some examples of Newton's First Law of Motion :

1. A person standing in a moving vehicle bends forward when the driver of vehicle applies brakes abruptly.

Explanation:This can be explained by applying the First law of motion. When the vehicle was moving the body of the person was also in motion. As the driver applies brakes the vehicle comes to rest and the feet of the person which were in contact with the vehicle also came to rest, but the upper part of the body of the person is still in motion. So because of inertia the person bends forward.

2. A stone lying on the floor is in the state of rest.

Explanation:This can be explained by applying the First law of motion. A stone is lying on the floor, so because of inertia the stone will remain there unless some unbalanced force is applied on it to change its state.

3. While getting down from a moving bus, a person should hit the ground running forward.

Explanation: This can be explained by applying the First Law of Motion. As the bus is moving the body of the person is also in motion.

.... (More Text Available, Login?)

Sample Questions

(More Questions for each concept available in Login)

Question : 1

An object continues to be in __________________ with the same speed and in same direction unless acted upon by an unbalanced force.
A. Motion	B. Force	C. Speed	D. None of these .
Right Option : A
View Explanation

Question : 2

When a bus starts suddenly, the passengers standing in it leans backwards in the bus. This is an example of
A. Newton's first law
B. Newton's second law
C. Newton's third law
D. None of Newton's laws
Right Option : A
View Explanation

Question : 3

If a body is at rest on the surface of the earth then which of the following statement is correct ?
A. No force is acting on the body		B. Only weight of the body acts on it
C. Net downward force is equal to the net upward force		D. None of these
Right Option : C
View Explanation