Embibe Experts Solutions for Chapter: Laws of Motion, Exercise 9: Exercise (Analytical Questions)

A ball of mass $250 \mathrm{gm}$ collides on the wall of the billiards tables with $2 \mathrm{m} {\mathrm{s}}^{-1}$. After remaining in contact with the surface for $0.02 \mathrm{s}$, it rebounds with $1.8 \mathrm{m} {\mathrm{s}}^{-1}$. Calculate approximately the magnitude of the average force exerted on the ball by the surface.

In the given diagram, the tension in the string $C$ is:- 

Three forces P, Q & R are acting at a point in a plane. The angle between P and Q, Q and R are 150° and 120° respectively. Then for equilibrium, forces P, Q & R are in the ratio :

A sphere of mass m is kept in equilibrium with the help of several springs as shown in the figure. Measurements show that one of the springs applies a force $\overrightarrow{\mathrm{F}}$. on the sphere. With what acceleration the sphere will move immediately after this particular spring is cut?

In the set-up shown, a 200 N block is supported in equilibrium with the help of strings and a spring, all knotted at point O. Extension in the spring is 4 cm. Force constant of the spring is closest to [g = 10 m/s²]
                                     

A lift of mass $100 \mathrm{kg}$ starts moving from rest in the upward direction. Figure shows the variation of speed of the lift. If T₁, T₂ and T₃ stand for tension in the rope from zero to two seconds, two to six seconds, six to seven seconds respectively, then :-
                                  

A pulley is attached to the ceiling of a lift moving upwards. Two particles are attached to the two ends of a string passing over the pulley. The masses of the particles are in the ratio 2 : 1. If the acceleration of the particles relative to the lift is g/2, then the acceleration of the lift will be

All surfaces are assumed to be frictionless. Calculate the horizontal force F that must be applied so that m₁ and m₂ do not move relative to m₃ is :-