Question

An object of mass 100 kg is accelerated uniformly from a velocity of 5 ms–1 to 8 ms–1 in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.

Answer 1

Numerical :

Given,

m = 100kg

v1= 5m/s

v2 =8m/s

t = 6sec

Case 1(a).

Initial momentum -

p =m×v1

p = 100×5

p= 500kgm/s

(b). final momentum

p=m×v2

p= 100×8

p=800kgm/s

Case 2. Magnitude of force.

First, we need to find accn of the body

We, know that accn

= (v2 - v1)÷t

= (8-5)/6

= 3/6

= 0.5m/s²

Now, we apply f = m×a

f = 100× 0.5

f = 50N

Hope it helps :)

Answer 2

Answer:

Known Terms:-

u = Initial speed

v = Final speed

m = Mass

t = Time.

F = Force.

Given:-

Initial velocity of the object, u = 5 m/s.

Final velocity of the object, v = 8 m/s.

Mass of the object, m  = 100 kg.

Time taken by the object, t = 6 sec.

To Find:-

1. Initial and Final momentum of the object.

2. Force exerted on the object.

Formula to be used:-

p = m v

F = Change of momentum / time taken.

Solution:-

Putting all values, we get

Initial momentum of the object

= m × v

= 100 × 5

= 500 kg m/s.

Final momentum of the object

= m × v

=  100 × 8

= 800 kg m/s.

F = Change of momentum / time taken.

F = (800 - 500) / 6

F = 300/6

F = 50 N.

Hence, Initial and Final momentum of the object are 500 kg m/s and 800 kg m/s and Force exerted on the object is 50 N.