Question

a body of mass 40 kg initially at rest is subjected to force of 16 newton. Calculate the kinetic energy acquired by the body at the end of 10th second​

Answer 1

$\large{\bf{\gray{\underline{\underline{\orange{Given:}}}}}}$

✠ Mass of body = 40kg

✠ Initial velocity = zero

✠ Applied force = 16N

$</p><p>\large{\bf{\gray{\underline{\underline{\green{To\:Find:}}}}}}$

✵ We have to find the kinetic energy acquired by the body at the end of 10th second.

$\large{\bf{\gray{\underline{\underline{\pink{Solution:}}}}}}$

➠ First of all, We need to find final velocity of body after the given interval of time.

➠ As per Newton's second law of motion, Force is defined as the rate of change of linear momentum.

• F = m(v - u) / Δt

❅ Final velocity of body :

⇒ F = m(v - u) / Δt

⇒ 16 = 40(v - 0) / 10

⇒ 40v = 160

⇒ v = 160/40

⇒ v = 4 m/s

❅ Kinetic energy of body :

➝ K = 1/2 × mv²

➝ K = 1/2 × 40 × (4)²

➝ K = 20 × 16

➝ K = 320J