Question

a force of 2n acting on a body changes its velocity uniformly from 2m/s to 5m/s in 10s.calculate the momentum of the body

Answer 1

a = v - u / t = 5 - 2 / 10 = 0.3 m/ sec^2
Since ,
F= m xa
m= F/a= 2 /0.3= 20 /3kg
Now,
Momentum = m x ( v-u)
=20 x 3 ÷3
= 20 kg m/sec

Answer 2

Given :

• Force (F) = 2 N

• Initial velocity (u) = 2 m/s

• Final velocity (v) = 5 m/s

• Time interval (t) = 10 s

To Find :

• Mass of the body

Solution :

Use 1st equation of motion for calculating value of acceleration :

$\\ \implies \boxed{\rm{v = u + at}} \\ \\ \\ \implies \rm{a = \dfrac{v - u}{t}} \\ \\ \\ \implies \rm{a = \dfrac{5 - 2}{10}} \\ \\ \\ \implies \rm{a = \dfrac{3}{10}} \\ \\ \\ \implies \rm{a = 0.3} \\ \\ \\ \underline {\rm{\therefore \: Acceleration \: of \: body \: is \: 0.3 \: ms^{-2}}}$

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Now, use formula of force

$\implies \boxed{\rm{F = ma}} \\ \\ \\ \implies \rm{m = \dfrac{F}{a}} \\ \\ \\ \implies \rm{m = \dfrac{2}{0.3}} \\ \\ \\ \implies \rm{m = 6.67} \\ \\ \\ \underline {\rm{\therefore \: Mass \: of \: body \: is \: 6.67 \: kg}}$