Motion In One Dimension Question 3
Question 3 - 25 January - Shift 2
The distance travelled by a particle is related to time $t$ as $x=4 t^{2}$. The velocity of the particle at $t=$ $5 s$ is .
(1) $40 ms^{-1}$
(2) $25 ms^{-1}$
(3) $20 ms^{-1}$
(4) $8 ms^{-1}$
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Answer: (1)
Solution:
Formula: Instantaneous velocity
$x=4 t^{2}$
$v=\frac{dx}{dt}=8 t$
At $t=5 sec$
$v=8 \times 5=40 m / s$.