Question

A force of 2N acting on a body changes its velocity uniformly from 3m/s to 5m/s in 10s . calculate the mass of the body

Answer 1

a=v-u/t=5-3/10=2/10=0.2m/s²
m=F/a= 2/0.2=10kg

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

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