MCQ
The motion of a particle is described by the equation $x = a + b{t^2}$ where $a = 15\, cm$ and $b = 3 \,cm/s^2$. Its instantaneous velocity at time $3\, sec$ will be........$cm/sec$
- A$36$
- ✓$18$
- C$16$
- D$32$
✓
Answer
Correct option: B.
$18$
b
(b) $x = a + b{t^2},\;v = \frac{{dx}}{{dt}} = 2bt$
(b) $x = a + b{t^2},\;v = \frac{{dx}}{{dt}} = 2bt$
Instantaneous velocity $v = 2 \times 3 \times 3 = 18\;cm/\sec $
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