Question

Answer is option(A)... explain the process...

Answer 1

Since work done=Energy
and here both vehicles have equal kinetic energy, so
KE1=KE2
=F.S1=F.S2 (since both have equal force)
=S1=S2

Hope you understand...!!

Answer 2

Heya friend
Here is your answer !!

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Let m1 , m2 be the mass and u1 , u2 be the initial velocities of the truck and car respectively .

As , K.E. of both are equal ,

So , 1/2 m1u1² = 1/2 m2u2²
or , m1 / m2 = u2² / u1² ... ( i )

As equal retarding force is applied on both then
0 = u1² - 2fS1 / m1 = m1u1² / 2f.
and , 0 = u2² - 2fS2 / m2
=> S2 = m2u2² / 2f

So , S1 / S2 = m1u1² / m2u2²

There fore , S1 / S2 = 1/1
or , S1 = S2

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Hope it helps !!