A body of mass 5 kg is moving with a momentum of 10 kg ms⁻¹. Now a force of 2 N acts on the body in the direction of its motion for 5 s. The increase in the Kinetic energy of the body is ___________ J. Numerical answer type. Work it out, then open the answer.

Answer: 30. Initial p₁ = 10 kg m/s; impulse = F t = 2 × 5 = 10 N s, so p₂ = 20 kg m/s. K = p²/2m: K₁ = 100/10 = 10 J, K₂ = 400/10 = 40 J Increase in KE = 40 - 10 = 30 J

A body of mass 5 kg is moving with a momentum of 10 kg ms⁻¹. Now a… | JEE Main 2023 (8 Apr, Shift 2)

Q12JEE Main 2023 · 8 APR · SHIFT 2Medium

Kinetic Energy & Momentum

A body of mass $5\text{ kg}$ is moving with a momentum of $10\text{ kg ms}^{-1}$ . Now a force of $2\text{ N}$ acts on the body in the direction of its motion for $5\text{ s}$ . The increase in the Kinetic energy of the body is ___________ $\text{J}$ .

Numerical answer type. Work it out, then open the answer.

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Answer: 30

Initial $p_1 = 10\text{ kg m/s}$ ; impulse $= F t = 2 \times 5 = 10\text{ N s}$ , so $p_2 = 20\text{ kg m/s}$ .
$K = \frac{p^2}{2m}$ : $K_1 = \frac{100}{10} = 10\text{ J}$ , $K_2 = \frac{400}{10} = 40\text{ J}$
Increase in KE $= 40 - 10 = 30\text{ J}$

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