Question

The velocity - time graph of a particle moving in a straight line is shown in figure. The mass of the particle is 2kg.Work done by all the forces acting on the particle in time interval between t = 0 to t = 10 s is

• A. 300 J
• B. −300 J
• C. 400 J
• D. −400 J

Answer 1

The correct option is A

300 J

From work - energy theorem,

W = $△KE=K_f-K_i=\frac{1}{2}m(v_f{}^2-v_i{}^2)$

=$\frac{1}{2}\times 2\left[\right(-20{)}^2-\left(10{)}^2\right]=300J$