Question

If the force is 5 newton due to which velocity changes from 1 m/sec to 3 m/sec in time 2 sec find intial and final momentum

Answer 1

Answer:

Let us suppose that we apply a force F to an object for Δt seconds. What does the quantity F · Δt represent?  

According to Newton's second law, the net force F on any object is related to its acceleration a and its mass m as follows:  

    F = m a , a is the acceleration  

a = Δv / Δt = (vf - vi) / Δt , acceleration is the change of velocity over time. vf is the final velocity and vi is the initial velocity. Δt is the interval of time over which the velocity changes from vi to vf.  

    F = m (Δv / Δt)  

From the above, we can write  

    F Δt = m Δv = m (vf - vi) = m vf - m vi = pf - pi  

F Δt represents the change in momentum and is called the impulse of the force F for the time interval Δt.  

A force F applied to an object for a time Δt gives rise to a change in momentum of the object.  

Explanation:

Answer 2

F = 5N

a = (3 - 1)/2 = 1

F = ma

m =5

initial momentum = 5*1= 5 kgm/s

final momentum = 5*3= 15kgm/s