Q.
A particle of mass 2 kg is initially at rest. A force acts on it whose magnitude changes with time. The force- time graph is shown below
The velocity of the particle after 10 s is
A) $20\ {ms}^{- 1}$
B) $10\ {ms}^{- 1}$
C) $75\ {ms}^{- 1}$
D) $50\ {ms}^{- 1}$
Explanation
(d) Are under the $F–t\ $cure=change in momentum
$or\ \ \frac{1}{2} \times 2 \times (10) + 2 \times 10 + \frac{1}{2}(10 + 20) \times 2 + \frac{1}{2} \times 4 \times 20 = m(v - u)$
$or\ 10 + 20 + 30 + 40 = 2(v - 0)$
$or\ \ 100 = 2v$
$or\ v = {50\ ms}^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.