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A car of mass m starts from rest and acq...

A car of mass m starts from rest and acquires a velocity along east `upsilon = upsilonhati (upsilon gt 0)` in two seconds Assuming the car moves with uniform acceleration the force exerted on the car is .

A

`(mv)/(2)` eastward and is exerted by the car engine

B

`(mv)/(2)` eastward and is due to the friction on the tyres exerted by the road

C

more than `(mv)/(2)` eastward exerted due to the engine and overcomes the friction of the road

D

`(mv)/(2)` exerted by the engine

Text Solution

Verified by Experts

The correct Answer is:
B
Given , mass of the car = m
As car starts from rest u = 0
Velocity acquired along east = `v hati`
Duration = t = 2s
We know that `" " v = u + at`
`implies " " vhati = o + a xx 2`
`implies " " a = (v)/(2) hati`
Force , `" " F = ma = (mv)/(2) hati`
Hence , force acting on the car is `(mv)/(2)` towards east . As external force on the system is only friction hence , the force `(mv)/(2)` is by friction . hence force , by engine is internal force .
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