In a car race, car A takes time t less than car B and passes the finishing point with a velocity v more than the velocity with which car B passes the point, Assuming that the cars start from rest and travel with constant accelerations a1 and a2 respectively, the value of 
is
Answers
11th
Physics
Motion in a Straight Line
Problems on Equation of Motion
In a car race, car A take...
PHYSICS
avatar
Asked on October 15, 2019 by
Prabhjit Honey
In a car race, car A takes a time t less than car B at the finish and passes the finishing point with speed v more than that of the car B. Assuming that both the cars starts from rest and travel with constant accelerations a
1
and a
2
respectively. So, the value of v will be :
medium
MEDIUM
Share
Save
ANSWER
Consider that A takes t
1
second, then according to the given problem, B will take (t
1
+t) seconds. Further let v
1
be the velocity of B at finishing point, then velocity of A will be (v
1
+v). Writing equations of motion for A and B
v
1
+v=a
1
t
1
....(i)
v
1
=a
2
(t
2
+t) ....(ii)
From equations (i) and (ii), we get
v=(a
1
−a
2
)t
1
−a
2
t .....(iii)
Total distance travelled by both the cars is equal
S
A
=S
B
⇒
2
1
a
1
t
1
2
=
2
1
a
2
(t
1
+t)
2
⇒t
1
=
a
1
−
a
2
a
2
t
Substituting this value of t
1
in equation (iii), we get
v=(
a
1
a
2
)t
Which book's question?