Laws of Motion ...

Two fixed frictionless inclined planes making an angle 30° and 60° with the vertical are shown in the figure. Two blocks A and B are placed on the two planes. What is the relative vertical acceleration of A with respect to B?

A rocket is propelled by a gas which is initially at a temperature of 4000 K. The temperature of the gas falls to 1000 K as it leaves the exhaust nozzle. The gas which will acquire the largest momentum while leaving the nozzle, is

Consider the following statement : When jumping from some height, you should bend your knees as you come to rest, instead of keeping your legs stiff. Which of the following relations can be useful in explaining the statement?
Where symbols have their usual meaning.

A false balance has equal arms. An object weigh X when placed in one pan and Y when placed in other pan, then the weight W of the object is equal to

In the arrangement shown in figure the ends P and Q of an unstrechable string move downwards with uniform speed U. Pulleys A and B are fixed. Mass M moves upwards with a speed

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system of remain inequilibrium, the angle θ should be

A string of negligible mass going over a clamped pulley of mass m supports a block of mass M as shown in the figure. The force on the pulley by the clamp is given by

A pulley fixed to the ceiling carries a string with blocks of mass m and 3m attached to its ends. The masses of string and pulley are negligible. When the system is released, its centre of mass moves with what acceleration?

A stick of 1 m is moving with velocity of 2.7 × 10⁸ms^–1. What is the apparent length of the stick? (c = 3 × 10⁸ms^–1)