Related InterviewSolutions

• A block of mass M lying on a smooth· horizontal surface is rigidly attached ·to a light horizontal ·spring of spring constant k. The other end of the spring is rigidly connected to a fixed wall. A stationary gun fires ·bullets of mass m each in horizontal direction with speed `upsilon_(0)` one after other. The bullets hit the block and get embedded to it. The first bullet hits the block at t=0, the second bullent hits at `t=2pisqrt((M+m)/(k))+2pisqrt((M+2m)/(k))` and so on. The maximum comression in the spring after the `n^(th)` bullet hits is :A. `(nm upsilon_(0)sqrt(k))/((M+nm)^(3//2))`B. `((M+nm)^(3//2))/(nm upsilon_(0)sqrt(k))`C. `(sqrt(nm upsilon_(0)k))/((M+nm)^(3//2))`D. `(nm upsilon_(0))/(sqrt(k(M+nm)))`
• On a smooth horizontal plane, a uniform string of mass M and length L is lying in the state of rest. A man of the same mass M is standing next to one end of the string. Now, the man starts collecting the string. Finally the man collects all the string and puts it in his pocket. What is the displacement of the man with respect to earth in the process of collection ? A. `(L)/(2)`B. `(L)/(4)`C. `(L)/(8)`D. none
• A man of mass M stands at one end of a stationary plank of length L, lying on a smooth surface. The man walks to the other end of the plank. If the mass of the plank is `M//3`, the distance that the man moves relative to the ground isA. `(3L)/(4)`B. `(L)/(4)`C. `(4L)/(5)`D. `(L)/(3)`
• At `t = 0`, the positions and velocities of two particles are as shown in the figure. They are kept on a smooth surface and being mutually attracted by gravitational force. Find the position of centre of mass at `t = 2s`. .A. X=5mB. X=7mC. X=3mD. X=2m
• A block of mass M is placed on the top of a bigger block of mass 10 M as shown in figure. All the surfaces are frictionless. The system is released from rest, then the distance moved by the bigger block at the instant the smaller block reaches the ground : A. 0.22 mB. 0.20 mC. zeroD. 0.24 m
• In an elastic collision of two billiard balls which of the following quantities is not conserved during the short time of collision :A. MomentumB. Total mechanical energyC. Kinetic energyD. None
• When a block is placed on a wedge as shown in figure, the block starts sliding down and the wedge also start sliding on ground. All surfaces are rough. The centre of mass of `(` wedge `+` block `)` system will move. A. upwardsB. downwardsC. leftwardsD. rightwards
• As shown in the figure a body of mass `m` moving horizontally with speed `sqrt(3) m//s` hits a fixed smooth wedge and goes up with a velocity `1v_(t)` in the vertical direction. If `/_` of wedge is `30^(@)`, the velocity `v_(f)` will be `:` A. `3 m//s`B. `sqrt(3) m//s`C. `(1)/(sqrt(3))m//s`D. this is not possible
• Two balls with masses in the ratio of 1:2 moving in opposite direction have a head-on elastic collision. If their velocities before impact were in the ration of 3:1, then velocities after impact will have the ratio :A. `5 :3`B. `7:5`C. `4:5`D. `2:3`
• The system of the wedge and the block connected by a massless spring as shown in the figure is released with the spring in its natural length. Friction is absent. Maximum elongation in the spring will be A. `(3Mg)/(5k)`B. `(6Mg)/(5k)`C. `(4Mg)/(5k)`D. `(8Mg)/(5k)`