Question

A force applied on a body of mass 4 kg for 5 sec changes it’s velocity from 10m/S to 20m/S . Find the required power

Answer 1

$\Large\underline{\underline{\sf \green{Given}:}}$

• Mass of body (m) = 4kg

• Time of force applied (T) = 5sec

• Initial Velocity (u) = 10m/s

• Final Velocity (v) = 20m/s

$\Large\underline{\underline{\sf \green{To\:Find}:}}$

• Required Power (P) = ?

$\Large\underline{\underline{\sf \green{Formula\:Used}:}}$

$\large{\boxed{\sf \red{Power=\frac{Work}{Time}}}}$

$\large{\boxed{\sf \red{K=\dfrac{1}{2}m(v^2-u^2)} }}$

$\large\underline{\underline{\sf \green{Solution}:}}$

$\implies{\sf K=\dfrac{1}{2}×4×(20^2-10^2) }$

$\implies{\sf K=\dfrac{1}{2}×4×(400-100) }$

$\implies{\sf K=600\:J }$

$\large\implies{\sf Power=\dfrac{Work}{Time}}$

$\implies{\sf P=\dfrac{600}{5} }$

$\implies{\sf P=120\:Watt}$

$\Large\underline{\underline{\sf \green{Answer}:}}$

⛬ Required Power is 120 Watt