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2 kg and 3 kg blocks are placed on a smooth horizontal surface and connected by a spring which is unstretched initially. The blocks are imparted velocities as shown in the figure. 3. Maximum speed of 2kg block in the subsequent motion will be a. 𝑣_0 b. 2𝑣_0 c. 3𝑣_0 d. 4𝑣_0

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2 kg and 3 kg blocks are placed on a smooth horizontal surface and connected by a spring which is unstretched initially. The blocks are imparted velocities as shown in the figure. 2. Maximum speed of 3kg block in the subsequent motion will be a. 𝑣_0 b. 2𝑣_0 c. 3𝑣_0 d. 4𝑣_0

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2 kg and 3 kg blocks are placed on a smooth horizontal surface and connected by a spring which is unstretched initially. The blocks are imparted velocities as shown in the figure. The maximum energy in the spring in the subsequent motion will be . a. 5𝑣_0^2 b. 15𝑣_0^2 c. zero d. 10𝑣_0^2

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A ball moving with a velocity v hits a massive wall moving towards the ball with a velocity u. An elastic impact lasts for time Δt. 1. The average elastic force acting on the ball is "m(u+v)" /"Δt." 2. The average elastic force acting on the ball is" 2m(u+v)" /"Δt." 3. The kinetic energy of the ball increases by 2mu(u+v). 4. The kinetic energy of the ball remains the same after the collision.

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A particle moving with kinetic energy 3 J makes an elastic head-on collision with a stationary particle which has twice its mass. During the impact,  (a) the minimum kinetic energy of the system is 1 J  (b) the maximum elastic potential energy of the system is 2 J  (c) momentum and total energy are conserved at every instant  (d) the ratio of kinetic energy to potential energy of the system first decreases and then increases

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A blast breaks a body initially at rest of mass 0.5kg into three pieces , two smaller pieces of equal mass and the third double the mass of either of small piece . After the blast two smaller masses move at right angles to one another with equal speed . Find the statements that is/are true for this case assuming that the energy of blast is totally transferred to masses. All the three pieces share the energy of blast equally The speed of bigger mass is √2 times the speed of either of the smaller mass The direction of motion of bigger makes an angle of 135° with the direction of smaller pieces The bigger pieces carries double the energy of either pieces

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Two charges moving under their only own mutual attraction separated by large distance initially. Then choose the correct statement(s) 1. If both are free, mechanical energy is conserved. 2. If one is fixed and other is free, mechanical energy is conserved. 3. If one is fixed and other is free, momentum is conserved. 4. If both are free momentum is conserved.

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X and Y component of acceleration of centre of mass are : 𝑎_(𝑐𝑜𝑚 𝑥)=(𝑚_1 𝑚_2 𝑔)/(𝑚_(1+) 𝑚_2 ) 𝑎_(𝑐𝑜𝑚 𝑥)=(𝑚_1 𝑚_2 𝑔)/〖𝑚_(1+) 𝑚_2〗^2 𝑎_(𝑐𝑜𝑚 𝑦)= 〖(𝑚_2/(𝑚_(1+) 𝑚_2 ))〗^2g 𝑎_(𝑐𝑜𝑚 𝑦)=(𝑚_2 𝑔)/〖𝑚_(1+) 𝑚_2〗^2

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In head on elastic collision of two bodies of equal masses, The velocities are interchanged The speeds are interchanged The momenta are interchanged The faster body speeds up and the slower body slows down

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For a two body system in absence of external forces, the kinetic energy as measured from ground frame is 𝐾_0 and from centre of mass frame is 𝐾_𝐶𝑀. Pick up the CORRECT statement. 1. The kinetic energy as measured from center of mass frame is least 2. Only the portion of energy 𝐾_𝐶𝑀 can be transferred from one form to another due to internal changes in the system. 3. The system always retains at least 𝐾_0- 𝐾_𝐶𝑀 amount of kinetic energy as measured from ground frame irrespective of any kind of internal changes in the system. 4. The system always retains at least K c m 𝐾 𝑐 𝑚 amount of kinetic energy as measured from ground frame irrespective of any kind of internal changes in the system.

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A man of mass `80 kg` stands on a plank of mass `40 kg`. The plank is lying on a smooth horizontal floor. Initianlly both are at rest. The man starts walking on the plank towards north and stops after moving a distance of `6 m` on the plank. Then 1. The centre of mass of plank-man system remains stationary 2. The plank will slide to the north by a dsitance `4m` 3. The plank will slide to the south by a distance `4 m` 4. The plank will slide to the south by a distance `12 m`

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