The correct sequence of reactions involved in the following conversion is

The percentage error in the measurement of mass and velocity are $3 \%$ and $4 \%$, respectively. The percentage error in the measurement of kinetic energy is

A car travelling at 80 kmph can be stopped at a distance of 60 m by applying brakes. If the same car travels at 160 kmph and the same braking force is applied, the stopping distance is

A 2 kg ball thrown vertically upward and another 3 kg ball projected with certain angle $\left(\theta \neq 90^{\circ}\right)$ both will have same time of flight, then this ratio of their maximum heights is