Question

a force of 100 N acts on a body of 2 kg for 10s. find the change in momentum of the body

Answer 1

Momentum (p) = mv

Where m is the mass and v is the velocity of body.

Change in momentum = mv2 - mv1 = m(v2 - v1) = m(∆v)

To calculate this we require mass and the change in velocity. Let's calculate the change in velocity.

Using the formula F=ma

100 = 2*a

a= 50 m/s^2

Now we know that acceleration is the rate of change of velocity or a = ∆v/t

∆v = a*t = 50*10 = 500 m/s

Change in momentum ∆p = 2*500 = 1000 kgm/s

Hope this helps..!!

Answer 2

F=m×a ,we know that acceleration is rate of change of velocity i.e. a=(v-u/t)

So the above equation can be written as

F=(mv-mu)/t

F×t=mv-mu

F×t=m×(v-u) here m(v-u) is change of momentum.

100×10=2×(v-u)

v-u=500 m/s.

Change of momentum=1000 kg-m/s.

Therefore,change in momentum in given problem is 1000 kg-m/s.