On a two-lane road,car A is travelling with a | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) First,convert all speeds to $m/s$: $v_A = 36 	imes (5/18) = 10 \; m/s$. $v_B = 54 	imes (5/18) = 15 \; m/s$. $v_C = 54 	imes (5/18) = 15 \; m/s

Vedclass · Accepted Answer

$1$

Vedclass · Answer

(B) First,convert all speeds to $m/s$: $v_A = 36 	imes (5/18) = 10 \; m/s$. $v_B = 54 	imes (5/18) = 15 \; m/s$. $v_C = 54 	imes (5/18) = 15 \; m/s$. Relative velocity of $B$ w.r.t $A$ is $v_{BA} = v_B - v_A = 15 - 10 = 5 \; m/s$. Relative velocity of $C$ w.r.t $A$ is $v_{CA} = v_C - (-v_A) = 15 + 10 = 25 \; m/s$. Distance $s = 1 \; km = 1000 \; m$. Time taken by car $C$ to reach car $A$ is $t = s / v_{CA} = 1000 / 25 = 40 \; s$. To avoid an accident,car $B$ must cover $1000 \; m$ in $t = 40 \; s$. Using the equation of motion $s = u_{BA}t + (1/2)at^2$: $1000 = 5 	imes 40 + (1/2) 	imes a 	imes (40)^2$. $1000 = 200 + 800a$. $800 = 800a$. $a = 1 \; m/s^2$.

Similar Questions

$A$ motorboat covers a given distance in $6 \,h$ moving downstream on a river. It covers the same distance in $10 \,h$ moving upstream. The time it takes to cover the same distance in still water is (in $\,h$)

If the velocities of object $A$ and $B$ are $v_A$ and $v_B$ respectively,then write the equation of the relative velocity of $A$ with respect to $B$.

$A$ bomb is dropped by a fighter plane flying horizontally. To an observer sitting in the plane,the trajectory of the bomb is a:

Two cars $A$ and $B$ are moving with a velocity of $30 \ km/h$ in the same direction. They are separated by $10 \ km$. The speed of another car $C$ moving in the opposite direction,if it meets these two cars at an interval of $8 \ minutes$,is: (in $km/h$)

$A$ man swimming downstream overtakes a float at a point $M$. After travelling a distance $D$,he turns back and passes the float at a distance of $D/2$ from the point $M$. The ratio of the speed of the swimmer with respect to still water $(v_s)$ to the speed of the river $(v_r)$ is:

Vedclass Test Series

Exam Paper Generator

Online Exam Module