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

Options

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

Answer

B

Explanation

`(mv)/(2 )` eastward and is due to the friction on the types exerted by the road
mass of the car = m
velocity along east `vec( v) = v hat(j )`
`v hat(j ) = 0 + a (2)`
Force F = ma
Force act on car in `(mv)/(2)` in east direction force acting on system is frictional froce `= (mv)/(2)`
force by enging will be interal force