List of top Physics Questions on Newtons Laws of Motion

A block of mass 2 kg is placed on a rough horizontal surface. If a horizontal force of 20 N acting on the block produces an acceleration of 7 m/s$^2$ in it, then the coefficient of kinetic friction between the block and the surface is (Acceleration due to gravity = 10 m/s$^2$)
A 2 kg brick begins to slide over a surface which is inclined at an angle of \( 45^\circ \) with respect to the horizontal axis. The coefficient of static friction between their surfaces is:
A light string passing over a smooth light fixed pulley connects two blocks of masses m1 and m2. If the acceleration of the system is g/8, then the ratio of masses is
A body of weight 200 N is suspended from a tree branch through a chain of mass 10 kg. The branch pulls the chain by a force equal to (if $g = 10 \, \text{m/s}^2$):
A 1 kg mass is suspended from the ceiling by a rope of length 4m. A horizontal force 'F' is applied at the mid point of the rope so that the rope makes an angle of 45° with respect to the vertical axis as shown in figure. The magnitude of F is
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A given object takes \(n\) times the time to slide down \(45^\circ\) rough inclined plane as it takes the time to slide down an identical perfectly smooth \(45^\circ\) inclined plane. The coefficient of kinetic friction between the object and the surface of inclined plane is:
The centripetal acceleration of a particle in uniform circular motion is \( 18 \, {ms}^{-2} \). If the radius of the circular path is \( 50 \) cm, the change in velocity of the particle in a time of \( \frac{T}{18} \) is:

Three blocks of masses 2 m, 4 m and 6 m are placed as shown in figure. If \( \sin 37^\circ = \frac{3}{5} \), \( \sin 53^\circ = \frac{4}{5} \), the acceleration of the system is:

A body of mass 4 kg is moving with a velocity 6 ms\(^{-1}\) on a smooth surface. If it is brought to rest in 4 s, the force applied is:
A block is kept on a rough horizontal surface. The acceleration of the block increases from \( 6 \ ms^{-2} \) to \( 11 \ ms^{-2} \) when the horizontal force acting on it increases from \( 20 \ N \) to \( 30 \ N \). The coefficient of kinetic friction between the block and the surface is: (Acceleration due to gravitiy = 10ms-^2)
A 7 kg object is subjected to two forces, \( F_1 = 20i + 30j \, \text{N} \) and \( F_2 = 8i - 50j \, \text{N} \). Find the acceleration of the object.

Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction between the trolley and the surface is 0.04, the acceleration of the system in m/s2 is : (Consider that the string is massless and unstretchable and the pulley is also massless and frictionless) :

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A bullet is fired into a fixed target looses one third of its velocity after travelling 4 cm. It penetrates further \( D \times 10^{-3} \) m before coming to rest. The value of \( D \) is :

All surfaces shown in figure are assumed to be frictionless and the pulleys and the string are light. The acceleration of the block of mass 2 kg is :
block of mass 2 kg
A fully charged capacitor \(C\) with initial charge \(q_0\) is connected to a coil of self-inductance \(L\) at \(t = 0\). The time at which the energy is stored equally in the form of electric field in the capacitor and the magnetic field in the inductor is:
Acceleration versus velocity graph of a particle moving in a straight line is as shown in the graph. The corresponding velocity–time graph would be
A man wishes to cross the river flowing with velocity \(v\) making angle \(\theta\) with y direction. If he swims with speed \(u\) and width of river is \(d\), the time taken will be
In a system, 8 kg mass is subjected to a force of 16 N along positive y axis and another 8 N along positive x axis. The angle made by acceleration of centre of mass with x axis is
A mass \(m\) moves with velocity \(v\) and collides elastically with another identical mass. After collision, the first mass moves with velocity \(\frac{v}{\sqrt3}\) in a direction perpendicular to the initial direction of motion. Find the speed of 2nd mass after collision.
A lift is moving in upward direction. The total mass of the lift and the passengers is 1600 kg. The variation of the velocity of lift is as shown in the figure. The tension in the rope at \(t = 8^{\text{th}}\) second will be
A block of mass 5 kg is placed on a rough horizontal surface with a coefficient of friction 0.5. If a horizontal force of 60 N is acting on it, then the acceleration of the block is (Acceleration due to gravity \( g = 10 \) ms\(^{-2}\)):
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 (Acceleration due to gravity \( g = 10 \) ms\(^{-2}\)):
A block of mass 18.5 kg kept on a smooth horizontal surface is pulled by a rope of 3 m length by a horizontal force of 40 N applied to the other end of the rope. If the linear density of the rope is 0.5 kgm\(^-1\) and initially the block is at rest, the time in which the block moves a distance of 9 m is
Two masses \( m_1 \) and \( m_2 \) are connected by a light string passing over a smooth pulley. When set free, \( m_1 \) moves downwards by 3 m in 3 s. The ratio of \( \frac{m_1}{m_2} \) is \((g = 10 \text{ m/s}^2)\).
Action and reaction can never balance out because