Question

A force F is applied to the initially stationary cart. The variation of force with time is shown in the figure. The speed of cart at t = 5 sec is -

• A. 10 m/s
• B. 8.33 m/s
• C. 2 m/s
• D. Zero

Answer 1

Answer: (B)

8.33 m/s

Answer 2

Parabola has equation

F= kt² …… (1)

50 = k (5)² k = 2

 F = 2t² ……… (2)

$m\frac{dv}{dt}$ = 2t²

$10\int_{0}^{v}{dv}$ = $2\int_{0}^{5}t^{2}dt$ 10 v = 2 $\left( \frac{t^{3}}{3} \right)_{0}^{5}$

v = 8.33 m/s