AIIMS Physics Laws Of Motion Class 11 Questions

The acceleration is given as, a = F/m = 20/2 = 10

A block weighs W is held against a vertical wall by applying a horizontal force F. The minimum value of F needed to hold the block is [ ]

Assertion: Even though the net external force on a body is zero, momentum needs to be conserved. Reason: The internal interactions between particles of a body cancel out momentum of each other.

A body of 5 kg weight kept on a rough inclined plane of angle 30° starts sliding with a constant velocity. Then the coefficient of friction is (assume g = 10 ms⁻²)

From Newton’s II law, a = F/m Higher the mass of the body, lower will be the acceleration that is mass of the body is a measure of the opposition offered by the body to change the state. Thus, the mass of the body is the measure of its inertia.

In the diagram 100 kg block is moving up with constant velocity, then find out the tension at point P:

If the block moves up with constant velocity v m/s. Find F,

A body of mass 40 kg resting on rough horizontal surface is subjected to a force P which is just enough to start the motion of the body. If μₛ = 5, μₖ = 0.4, g = 10 m/s², and the force P is continuously applied on the body, then the acceleration of the body is

A cart of mass 150 kg is pulled horizontally on a frictionless surface with force 10 N. If 100 g/s sand is being dropped in the cart vertically then find the speed of the system when cart has 100 kg sand in it.

The apple will fall slightly away from the hand of his brother in the direction of motion of the train due to inertia of motion. When train is just going to stop, the boy and his brother slows down with train but the apple which is in free fall continue to move with the same speed. So, the apple will falls slightly away from the hand in the direction of motion of the train.

It is given that, m₁ = 1 kg, m₂ = 6 kg, F = 6 N. The Mass of first block is more than the mass of second block and force applied on each ther is same. F = (m₁ + m₂)a, a = F / (m₁ + m₂), a = 6 / (1 - 0.5) = 12 m/s²

Consider the diagram shown below in which two masses of m and 2m are placed on a fixed triangular wedge. The coefficient of friction between block A and the wedge is 2/3, while that for block B and the wedge is 1/3. If the whole system is released from rest, then acceleration of block A is

A person of mass 60 kg is inside a lift of mass 940 kg and presses the button on control panel. The lift starts moving upwards with an acceleration 1 m/s². If g = 10 m/s², the tension in the supporting cable is

The mass of the ball: m = 10 g = 0.01 kg rebounds after striking the wall. Impulse = Change in momentum = mv - (-mv) = 2mv

Assertion: A quick collision between two bodies is more violent than slow collision, even when initial and final velocities are identical. Reason: The rate of change of momentum determines that the force is small or large.

A lift is moving in upward direction. The total mass of the lift and the passenger is 1600 kg. The variation of the velocity of the lift is as shown in the figure. The tension in the rope at t = 8 s will be

Four blocks of same mass connected by a string are pulled by a force F on a smooth horizontal surface as shown in the figure. The tension T₁, T₂, T₃ will be,

Photoelectric effect experiments are performed using three different metal plates p, q and r having work functions $Q_p = 2.0\text{ eV}$, $Q_q = 2.5\text{ eV}$ and $Q_r = 3.0\text{ eV}$ respectively. A light beam containing wavelengths of $550\text{ nm}$, $450\text{ nm}$ and $350\text{ nm}$ with equal intensities illuminates each of the plates. The correct I-V graph of the experiment is (take $hc = 1240\text{ eV}\cdot\text{nm}$)

Consider the system shown in figure. The pulley and the string are light and all the surfaces are frictionless. The tension in the string is (take g = 10 m s⁻²)

A body of mass $40\text{ kg}$ resting on rough horizontal surface is subjected to a force P which is just enough to start the motion of the body. If $\mu_s = 5, \mu_k = 0.4$, $g = 10\text{ m/s}^2$ and the force P is continuously applied on the body, then the acceleration of the body is

A uniform disc is acted by two equal forces of magnitude $F$. One of them, acts tangentially to the disc, while other one is acting at the central point of the disc. The friction between disc surface and ground surface is $nF$. If $r$ be the radius of the disc, then the value of $n$ would be (in N)

A massless rod S having length $2l$ has equal point masses attached to its two ends as shown in figure. The rod is rotating about an axis passing through its centre and making angle $\theta$ with the axis. The magnitude of change of angular momentum of rod i.e. $\left|\frac{d\vec{L}}{dt}\right|$ equals

Consider the diagram shown below in which two masses of m and 2m are placed on a fixed triangular wedge. The coefficient of friction between block A and the wedge is 2/3, while that for block B and the wedge is 1/3.

A ball of mass m is tied up with string and rotated along a horizontal circle of radius r. At an instant, its velocity is v, and tension in string is T, the force required for circular motion is

Given that force (5î + 7ĵ − 3k̂) N acts on a particle at position (î + ĵ − k̂) m. Find torque of this force on the particle about origin.

Assertion: Animate object can accelerate in the absence of external force. Reason: Newton's second law is not applicable on animate object.

A 0.2 kg object at rest is subjected to a force .(0.3î−0.4ĵ) N. What is the velocity after 6 s?

Two masses M₁ = 5 kg and M₂ = 10 kg are connected at the ends of an inextensible string passing over a frictionless pulley as shown. When the masses are released, then the acceleration of the masses will be

Assertion: The apparent weight of a body in an elevator moving with some downward acceleration is less than the actual weight of a body. Reason: The part of the weight is spent in producing downward acceleration, when body is in elevator.

Assertion: A horse has to pull a cart harder during the first few steps of his motion. Reason: The first few steps are always difficult.

Three equal weights of 3 kg each are hanging on a string passing over a frictionless pulley as shown in figure. The tension in the string between masses II and III will be (Take g = 10 m/sec²)

Assertion : Impulsive force is large and acts for a short time. Reason : Finite change in momentum should be produced by the force.

A man of mass 60 kg records his wt. on a weighing machine placed inside a lift. The ratio of wts. of man recorded when lift is ascending up with a

A person used force (F₀), shown in figure to move a load with constant velocity on surface. Identify the correct surface profile.

Assertion : Use of ball bearings between two moving parts of a machine is a common practice. Reason : Ball bearings reduce vibrations and provide good stability.

In the figure given, the position-time graph of a particle of mass 0.1 kg is shown. The impulse at t = 2 sec is

A ladder is leaned against a smooth wall and it is allowed to slip on a frictionless floor. Which figure represents trace of its centre of mass.

A person is standing in an elevator. In which situation he finds his weight less?

Assertion : Frictional forces are conservative forces. Reason : Potential energy can be associated with frictional forces.

Assertion : It is difficult to move a cycle along the road with its brakes on. Reason : Sliding friction is greater than rolling friction.

A man waves his arms while walking. This is