Question

Using Newton's 2nd law derive 1st equation of motion

Answer 1

According to the Newton’s 2nd Law of motion, the rate of change of linear momentum of a body is directly proportional to the applied external force and in the direction of force.

Consider a body of mass ‘m’ moving with velocity v.

The linear momentum of a body is given by:

p = mv

Now According to Newton’s 2nd Law of Motion:

Force is directly proportional to rate of change of momnetum, that is

F α dp/dt

F = k dp/dt

F = k d(mv)/dt

F = k md(v)/dt

F = k ma

If m= 1 unit and a = 1 unit, we define F = 1 so that k =1

For example if m = 1 kg, a = 1m/s^2 and k= 1 , then F is called 1 Newton.

Answer 2

hope this will help you