A car of mass $m$starts from rest and acquires a velocity along east, $\mathbf{v}=v\hat{\mathbf{i}}(v>0)$ in two seconds. Assuming the car moves with uniform acceleration, the force exerted on the car is

At the point when surfaces in contact move comparative with one another, the friction between the two surfaces changes over kinetic energy into thermal energy (that is, it changes work over to warm). This property can have sensational results, as outlined by the utilization of friction made by scouring bits of wood together to light a fire.

$\text{ A car of mass }m\text{ starts from rest and acquires a velocity along east, }\mathbf{v}=v\hat{\mathbf{1}}(v>0)\text{ in two seconds. }$

The mass of the car is $m$ and the time taken is $t=2s$ .

let its initial velocity be 0. i.e. $u=0$ and final velocity $v$ along the east direction.

applying, $v=u+at$

$v=0+\overline{a}\times 2$

$\therefore \overline{a}=\frac{v}{2}i$

now due to friction on the tires exerted by the road, the force of the car is,

$$\begin{gathered} F=ma \\ \Rightarrow F=\frac{mv}{2} \end{gathered}$$ Force is eastward and is due to the friction on the tires exerted by the road.

the force exerted on the car is $\frac{mv}{2}$ eastward and is due to the friction on the tires exerted by the road.

Hence the correct option is (2).