NEET Physics Laws Of Motion Class 11 Questions

Figures (a), (b), (c) and (d) show variation of force with time. The impulse is highest in figure.

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)

A body with mass 5 kg is acted upon by a force F = (−3î + 4ĵ)N. If its initial velocity at t = 0 is v = (6î − 12ĵ) ms⁻¹, the time at which it will just have a velocity along the Y⁻axis is

When the elevator moves upward with constant acceleration

A gun fires a bullet of mass 50 g with a velocity of 30 m sec⁻¹. Because of this the gun is pushed back with a velocity of 1 m sec⁻¹. The mass of the gun is

A box of mass 15 kg is kept on the floor of a stationary trolley. The coefficient of static friction between the box and the trolley is 0.12. Keeping the box in stationary state over the trolley, the maximum acceleration with which the trolley can be moved horizontally in m s⁻² is: (g = 10 m/s²)

The magnitude and direction of the acceleration produced in a body of mass 5 kg when two mutually perpendicular forces 8 N and 6 N act on it, are respectively:

There are two inclined surfaces of equal length (L) and same angle of inclination 45° with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as much time to slide down on rough surface than on the smooth surface. The coefficient of kinetic friction (μₖ) between the object and the rough surface is close to

A uniform rod of mass 20 kg and length 5 m leans against a smooth vertical wall making an angle of 60° with it. The other end rests on a rough horizontal floor. The friction force that the floor exerts on the rod is (take g = 10 m/s²)

A bob is whirled in a horizontal plane by means of a string with an initial speed of \( \omega \) rpm. The tension in the string is T. If speed becomes 2 \( \omega \) while keeping the same radius, the tension in the string becomes:

A horizontal force 10 N is applied to a block A as shown in figure. The mass of blocks A and B are 2 kg and 3 kg, respectively. The blocks slide over a frictionless surface. The force exerted by block A on block B is:

A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is:

Calculate the maximum acceleration of a moving car so that a body lying on the floor of the car remains stationary. The coefficient of static friction between the body and the floor is 0.15 (g = 10 m s⁻²).

A small block slides down on a smooth inclined plane, starting from rest at time t = 0. Let Sₙ be the distance travelled by the block in the interval t = n−1 to t = n. Then, the ratio \( \frac{S_n}{S_{n+1}} \) is :

A ball of mass 0.15 kg is dropped from a height 10 m, strikes the ground and rebounds to the same height. The magnitude of impulse imparted to the ball is (g = 10 m/s²) nearly:

Two bodies of mass 4 kg and 6 kg are tied to the ends of a massless string. The string passes over a pulley which is frictionless (see figure). The acceleration of the system in terms of acceleration due to gravity (g) is:

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

A body weighs 200 N on the surface of the earth. How much will it weigh half way down to the centre of the earth?

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 g for the block to remain stationary on the wedge is

Which one of the following statements is incorrect?

Two blocks A and B of masses 3m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively:

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 A of mass m₁ rests on a horizontal table. A light string connected to it passes over a frictionless pulley at the edge of table and from its other end another block B of mass m₂ is suspended. The coefficient of kinetic friction between the block and table is μₖ. When the block A is sliding on the table, the tension in the string is

Three blocks A, B and C of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface, as shown. If force of 14 N is applied on the 4 kg block, then the contact force between A and B is

A system consists of three masses m₁, m₂ and m₃ connected by a string passing over a pulley P. The mass m₁ hangs freely and m₂ and m₃ are on a rough horizontal table (the coefficient of friction = μ). The pulley is frictionless and of negligible mass. The downward acceleration of mass m₁ is (Assume m₁ = m₂ = m₃ = m)

A balloon with mass m is descending down with an acceleration a (where a < g). How much mass should be removed from it so that it starts moving up with an acceleration a?

A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/s. A bob is suspended from the roof of the car by a light wire of length 1.0 m. The angle made by the wire with the vertical is:

A person holding a rifle (mass of person and rifle together is 100 kg) stands on a smooth surface and fires 10 shots horizontally in 5 s. Each bullet has a mass of 10 g with a muzzle velocity of 800 m/s. The final velocity acquired by the person and the average force exerted on the person are: