Velocity-time graph of a particle of mass 2 kg moving in a straight line is as shown in figure. Work done by all forces on the particle is

Question

Velocity-time graph of a particle of mass 2 kg moving in a straight line is as shown in figure. Work done by all forces on the particle is (A) 400 J (B) -400 J (C) -200 J (D) 200 J

Tardigrade Admin · Accepted Answer

Initial velocity of particle, vi=20 ms -1 Final velocity of the particle, vf=0 According to work-energy theorem W text net =Δ KE =Kf-Ki =(1/2) m(vf2-vi2) =(1/2) × 2(02-202)=-400 J

Q. Velocity-time graph of a particle of mass $2 k g$ moving in a straight line is as shown in figure. Work done by all forces on the particle is

400 J

-400 J

-200 J

200 J

Initial velocity of particle, $v_{i} = 20 m s^{- 1}$
Final velocity of the particle, $v_{f} = 0$
According to work-energy theorem
$W_{net} = Δ K E = K_{f} - K_{i}$
$= \frac{1}{2} m (v_{f}^{2} - v_{i}^{2})$
$= \frac{1}{2} \times 2 (0^{2} - 2 0^{2}) = - 400 J$

Q. Velocity-time graph of a particle of mass 2kg moving in a straight line is as shown in figure. Work done by all forces on the particle is