A stone is projected vertically upwards with velocity 'V. Another stone of same mass is projected at an angle fo $$60^{\circ}$$ with the vertical with the same speed $$(\mathrm{V})$$. The ratio of their potential energies at the highest points of their journey, is

$$\left[\sin 30^{\circ}=\cos 60^{\circ}=0.5, \cos 30^{\circ}=\sin 60^{\circ}=\frac{\sqrt{3}}{2}\right]$$

A car of mass '$$m$$' moving with velocity '$$u$$' on a straight road in a straight line, doubles its velocity in time t. The power delivered by the engine of a car for doubling the velocity is

A bob of a simple pendulum of mass 'm' is displaced through 90$$^\circ$$ from mean position and released. When the bob is at lowest position, the tension in the string is

Three bodies P, Q and R have masses 'm' kg, '2m' kg and '3m' kg respectively. If all the bodies have equal kinetic energy, then greater momentum will be for body/bodies.