Two cars A and B at rest at same point initially. If A starts with uniform velocity of 40, m/sec and

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2.Motion in Straight Line

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Two cars $A$ and $B$ at rest at same point initially. If $A$ starts with uniform velocity of $40\, m/sec$ and $B$ starts in the same direction with constant acceleration of $4\,m/{s^2}$, then $B $ will catch $A$ after how much time.........$sec$

A

$10$

B

$20$

C

$30$

D

$35$

Solution

(b) Let $A$ and $B$ will meet after time $t$ sec. it means the distance travelled by both will be equal.

${S_A} = ut = 40t$ and ${S_B} = \frac{1}{2}a{t^2} = \frac{1}{2} \times 4 \times {t^2}$

${S_A} = {S_B} \Rightarrow 40t = \frac{1}{2}4{t^2} \Rightarrow t = 20\,sec$

Standard 11

Physics

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(AIIMS-2016)