STANDARD Physics Laws Of Motion Class 11 Questions

Inertia is that property of a body by virtue of which the body is

When a speeding bus stops suddenly, passengers are thrown forward from their seats because

A constant force acting on a body of mass of 5 kg change its speed from 5 m s⁻¹ to 10 m s⁻¹ in 10 s without changing the direction of motion. The force acting on the body is

A bullet of mass 40 g moving with a speed of 90 m s⁻¹ enters a heavy wooden block and is stopped after a distance of 60 cm. The average resistive force exerted by the block on the bullet is

A body under the action of a force F = 6î - 8ĵ N acquires an acceleration of 5 m s⁻². The mass of the body is

A constant retarding force of 50 N is applied to a body of mass 10 kg moving initially with a speed of 10 m s⁻¹. The body comes to rest after

A body of mass 5 kg starts from the origin with an initial velocity u = (30î + 40ĵ) m s⁻¹. If a constant force (-6î - 5ĵ) N acts on the body, the time in which the y-component of the velocity becomes zero is

A body of mass 0.4 kg starting at origin at t = 0 with a speed of 10 m s⁻¹ in the positive x-axis direction is subjected to a constant F = 8 N towards negative x-axis. The position of the body after 25 s is

Two masses m₁ = 1 kg and m₂ = 2 kg are connected by a light inextensible string and suspended by means of a weightless pulley as shown in the figure. Assuming that both the masses start from rest, the distance travelled by the centre of mass in two seconds is (Take g = 10 m s⁻²)

If the force on a rocket, moving with a velocity of 300 m s⁻¹ is 210 N, then the rate of combustion of the fuel is

A ball of mass m strikes a rigid wall with speed u and rebounds with the same speed. The impulse imparted to the ball by the wall is

The position-time graph of a body of mass 2 kg is as shown in figure. What is the impulse on the body at t = 4 s?

A stone of mass 1 kg is lying on the floor of a train which is accelerating with 1 m s⁻². The net force acting on the stone is

A rocket with a lift-off mass 2 × 10⁴ kg is blasted upwards with an initial acceleration of 5 m s⁻². The initial thrust of the blast is (Take g = 10 m s⁻²)

A ball of mass m strikes a rigid wall with speed u at an angle of 30° and gets reflected with the same speed and at the same angle as shown in the figure. If the ball is in contact with the wall for time t, then the force acting on the wall is

A rocket of initial mass 6000 kg ejects gases at a constant rate of 16 kg s⁻¹ with constant relative speed of 11 km s⁻¹. What is the acceleration of the rocket one minute after the blast?

A shell of mass 200 g is fired by a gun of mass 100 kg. If the muzzle speed of the shell is 80 m s⁻¹, then the recoil speed of the gun is

A 100 kg gun fires a ball of 1 kg horizontally from a cliff of height 500 m. It falls on the ground at a distance of 400 m from the bottom of the cliff. The recoil velocity of the gun is (Take g = 10 m s⁻²)

A rigid ball of mass m strikes a rigid wall at 60° and gets reflected without loss of speed as shown in the figure. The value of impulse imparted by the wall on the ball will be

A body is moving under the action of two forces F₁ = 2î - 5ĵ ; F₂ = 3î - 4ĵ. Its velocity will become uniform under a third force F₃ given by

A block of mass m rests on a rough inclined plane. The coefficient of friction between the surface and the block is μ. At what angle of inclination θ of the plane to the horizontal will the block just start to slide down the plane?

The minimum force required to start pushing a body up a rough (frictional coefficient μ) inclined plane is F₁ while the minimum force needed to prevent it from sliding down is F₂. If the inclined plane makes an angle θ with the horizontal such that tan θ = 2μ, then the ratio \( \frac{F_1}{F_2} \) is

A simple pendulum of length 1 m has a wooden bob of mass 1 kg. It is struck by a bullet of mass 10⁻² kg moving with a speed of 2 × 10² m s⁻¹. The height to which the bob rises before swinging back is (Take g = 10 m s⁻²)

A block of mass 10 kg is placed on rough horizontal surface whose coefficient of friction is 0.5. If a horizontal force of 100 N is applied on it, then acceleration of the block will be [Take g = 10 m s⁻²]

The coefficient of static friction between the box and the train's floor is 0.2. The maximum acceleration of the train in which a box lying on its floor will remain stationary is (Take g = 10 m s⁻²)

A block of mass 1 kg lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is 0.6. If the acceleration of the truck is 5 m s⁻². The frictional force acting on the block is

A block of mass 2 kg rest on a plane inclined at an angle of 30° with the horizontal. The coefficient of friction between the block and the surface is 0.7. What will be the frictional force acting on the block? (take g = 9.8 m/s²)

A block of mass M is held against a rough vertical wall by pressing it with a finger. If the coefficient of friction between the block and the wall is μ and the acceleration due to gravity is g, what is the minimum force required to be applied by the finger to hold the block against the wall?

A trolley of mass 20 kg is attached to a block of mass 4 kg by a massless string passing over a frictionless pulley as shown in the figure. If the coefficient of kinetic friction between trolley and the surface is 0.02, then the acceleration of the trolley and block system is (Take g = 10 m s⁻²)

In figure, the coefficient of friction between the floor and the block B is 0.1. The coefficient of friction between the blocks B and A is 0.2. The mass of A is m/2 and of B is m. What is the maximum horizontal force F which can be applied to the block B so that two blocks move together?

A car moving with a speed of 50 km h⁻¹ can be stopped by applying brakes after moving at least 6 m. If the same car is moving at a speed of 100 km h⁻¹ the minimum stopping distance is

Two blocks A and B of masses 10 kg and 15 kg are placed in contact with each other rest on a rough horizontal surface as shown in the figure. The coefficient of friction between the blocks and surface is 0.2. A horizontal force of 200 N is applied to block A. The acceleration of the system is

A bullet fired into a wooden block loses half of its velocity after penetrating 40 cm. It comes to rest after penetrating a further distance of

The coefficient of friction between the tyres and the road is 0.1. The maximum speed with which a cyclist can take a circular turn of radius 3 m without skidding is (Take g = 10 m s⁻²)

A stone of mass 5 kg is tied to a string of length 10 m and is whirled round in a horizontal circle. What is the maximum speed with which the stone can be whirled around if the string can withstand a maximum tension of 200 N?

A person of mass 50 kg stands on a weighing scale on a lift. If the lift is ascending upwards with a uniform acceleration of 9 m s⁻², what would be the reading of the weighing scale? (Take g = 10 m s⁻²)

Block A of weight 100 N rests on a frictionless inclined plane of slope angle 30° as shown in the figure. A flexible cord attached to A passes over a frictionless pulley and is connected to block B of weight W. Find the weight W for which the system is in equilibrium.

Two blocks of masses 10 kg and 20 kg are connected by a massless string and are placed on a smooth horizontal surface as shown in the figure. If a force F = 600 N is applied to 10 kg block, then the tension in the string is

A monkey of mass 40 kg climbs on a massless rope which can stand a maximum tension of 500 N. In which of the following cases will the rope break? (Take g = 10 m s⁻²)

A mass of 1 kg is suspended by means of a thread. The system is (i) lifted up with an acceleration of 4.9 m s⁻² (ii) lowered with an acceleration of 4.9 m s⁻². The ratio of tension in the first and second case is

A car is negotiating a curved road of radius R. The road is banked at an angle θ. The coefficient of friction between the tyres of the car and the road is μₛ. The maximum safe velocity on this road is

A block of mass 10 kg is kept on a rough inclined plane as shown in the figure. A force of 3 N is applied on the block. The coefficient of static friction between the plane and the block is 0.6. What should be the minimum value of force P, such that the block does not move downward? (Take g = 10 m s⁻²)

A particle moving with velocity v is acted by three forces shown by the vector triangle PQR. The velocity of the particle will

A block of mass m is placed on a smooth inclined wedge ABC of inclination θ as shown in the figure. The wedge is given an acceleration a towards the right. The relation between a and θ for the block to remain stationary on the wedge is

A uniform ladder 3 m long weighing 20 kg leans against a frictionless wall. Its foot rests on a rough floor 1 m from the wall. The reaction forces of the wall and floor are