Laws of Motion ...

A block can slide on a smooth inclined plane of inclination θ kept on the floor of a lift. When the lift is descending with a retardation a, the acceleration of the block relative to the incline is

A 60 kg man stands on a spring scale in the lift. At some instant he finds, scale reading has changed from 60 kg to 50 kg for a while and then comes back to the original mark.
What should we conclude?

Three weights A, B and C are connected by string as shown in the figure. The system moves over a frictionless pulley. The tension in the string connecting A and B is (where g is acceleration due to gravity)

The masses of 10 kg and 20 kg respectively are connected by a massless spring as shown in figure. A force of 200 N acts on the 20 kg mass. At the instant shown, the 10 kg mass has acceleration 12 m/sec².
What is the acceleration of 20 kg mass?

A spring balance and a physical balance are kept in a lift. In these balances equal masses are placed. If now the lift starts moving upwards with constant acceleration, then

As shown in the figure, two equal masses each of 2 kg are suspended from a spring balance. The reading of the spring balance will be

A player kicks a football of mass 0.5 kg and the football begins to move with a velocity of 10 m/s. If the contactbetween the leg and the football lasts for 1/50s, then theforce acted on the football should be

The engine of a jet aircraft applies a thrust force of 10⁵N during take off and causes the plane to attain a velocity of 1 km/s in 10 s. The mass of the plane is

Two weights w₁ and w₂ are suspended from the ends ofa light string passing over a smooth fixed pulley. If the pulley is pulled up at an acceleration g, the tension inthe string will be

Two masses M and m are connected by a weightless string. They are pulled by a force F on a frictionless horizontal surface. The tension in the string will be