Related InterviewSolutions

• A weight lifter jerks `220 kg` vertically through `1.5` metre and holds still at that height for two minutes. The work done by him in lifting and in holding it still are respectivelyA. `220 J, 330 J`B. `3234J, 0 J`C. `2334 J, 10 J`D. `0 J, 3234 J`
• A board is moving with velocity `v` on a smoother horizontal plane. The upper surface of the board is rough on which a ball falls with velocity `v` and rebounds with velocity `(v)/(2)`. The mass of the board is same as that of ball. After the collision, the board comes to state of rest. The co-efficient of friction between the board and the ball isA. `(1)/(2)`B. `(2)/(3)`C. `(1)/(4)`D. `(3)/(5)`
• An object of mass 5 kg falls from rest through a vertical distance of `20 m` and attains a velocity of 10 m/s. How much work is done by the resistance of the air on the objrct? `(g=10m//s^(2))`.A. `750J`B. `-750 J`C. `850 J`D. `-650 J`
• A massless spring with a force constant `K = 40N//m` hangs vertically from the ceiling.A `0.2 kg` block is attached to the end of the spring and held in such a position that the spring has its natural length and suddenyl released. The maximum elastic strain energy stored in the spring is `(g=10 m//s^(2))`A. `0.1J`B. `0.2J`C. `0.05J`D. `0.4J`
• A ball of mass m is thrown in air with speed `v_(1)` from a height `h_(1)` and it is at a height `h_(2)(gth_(1))` when its speed becomes `v_(2)` . Find the work done on the ball the air resistance.A. `m g(h_(2)-h_(1))+(1)/(2)m(v_(2)^(2)-v_(1)^(2))`B. `m g(h_(2)-h_(1))`C. `(1)/(2)m(v_(2)^(2)-v_(1)^(2))`D. `m g (h_(2)-h_(1))-(1)/(2)(v_(2)^(2)-v_(1)^(2))`
• A stone of mass `6 kg` is revolved in a vertical circle of diameter `6m`., such that its speed is minimum at a point. If the `K.E` at the same point is `250 J`, then minimum `PE` at that point isA. `200 J`B. `150 J`C. `100 J`D. `450 J`
• A car is travelling along a flyover bridge which is a part of vertical circle of radius `10m`. At the highest point of it the normal reaction on the car is half of it’s weight, the speed of car isA. `7m//s`B. `10m//s`C. `14m//s`D. `20m//s`
• A vehicle is travelling with uniform speed along a concave road of radius of curvature `19.6m`. At lowest point of concave road is the normal reaction on the vehicle is three times its weight, the speed of vehicle isA. `4.9 m//s`B. `9.8 m//s`C. `14.7 m//s`D. `19.6 m//s`
• A vehicle of mass 1000 kg is moving with a velocity of `15 ms^(-1)`.It is brought to rest by applying brakes and locking the wheels. If the slidding friction between the tyres and the road is 6000 N, then the distance moved by the vehicle before coming to rest isA. `37.5 m`B. `18.75m`C. `75m`D. `15 m`
• A projectile of mass `50 kg` is shot vertically upwards with n initial velocity of `100m//s`. After `5s`, it explodes into two fragments, one of (1st fragment) which having a mass of `20 kg` travels vertically up with a velovity of `150m//s (g = 10 m//s^(2))`. Bases on the above paragraph answer the following questions. What is the magnitude and direction of velocity of the 2nd fragments just after explosion isA. `(50)/(3)m//s` (up)B. `50m//s` (down)C. `50m//s`D. `(50)/(3)m//s` (down)