Related InterviewSolutions

• A heavy box of mass 20 kg is pulled on a horizontal surface by applying a horizontal force. If the coefficient of kinetic friction between the box and the horizontal surface is 0.25, find the force of friction exerted by the horizontal surface on the box.A. 5 NB. 10 NC. 50 ND. 200 N
• Block A weighs `4 N` and block weigh `8 N` The coefficient of kinetic friction is `0.25` for all surface find the force `F` to slide `B` at a constant speed when (a)`A` rest on `B` and moves with it (b) `A` is held at rest and (c )`A and B` are connected by a light cord passing over a smooth putting as shown in fig 7.31 (a - c) restively.
• A block slides down a rough inclined plane of slope angle `theta` with a constnat velocity. It is then projected up the same plane with an intial velocity v the distance travelled by the block up the plane coming to rest is .
• A block of mass M = 4 kg is kept on a smooth horizontal plane. A bar of mass m = 1 kg is kept on it. They are connected to a spring as shown & the spring is compressed. Then what is the maximum compression in the spring for which the bar will not slip on the block when released if coefficient of friction between them is 0.2 & spring constant = 1000 N/m : (Take `g=10m//s^(2)`) A. 1 cmB. 1 mC. 1.25 cmD. 10 cm
• A block takes a twice as much time to slide down a `45^(@)` rough inclined plane as it takes to slide down a similar smooth , plane . The coefficient of friction is :A. `(3)/(4)`B. `(sqrt3)/(2)`C. `(1)/(4)`D. `(1)/(3)`
• A ball of mass `m` is rotating in a circle of radius `r` with speed `v` inside a smooth cone as shown in figure. Let `N` be the normal reaction on the ball by the cone, then choose the correct option: A. `N cos theta = mg`B. `g sin theta = (v^(2))/(r) cos theta `C. `N sin theta - (mv^(2))/(r) = 0`D. none of these
• A block lying on a long horizontal conveyer belt moving at a constant velocity receives a velocity `v_(0) = 5m//s` relative to the ground in the direction opposite to the direction of motion of the conveyer. After `t = 4s`, the velocity of the block becomes equal to the velocity of the belt. The coefficient of friction between the block and the belt is `mu = 0.2`. Determine the velocity v of the conveyer belt.A. 3 m/sB. 5 m/sC. 4 m/sD. 7 m/s
• Calculate `F` such that frictional force acting on all blocks zero.
• A ball weighing `10g` hits a hard surface vertically with a speed of `5m//s` and rebounds with the same speed The ball remains in contact with the surface speed The ball remains in contact with the surface for `0.01s` The average force exerted by the surface on the ball is .A. 100 NB. 10 NC. 1ND. `0.1` N
• (A) : Polishing a surface beyond a certain limit increases rather than decreases the frictional forces . (R) : When the surface is polished beyond a certain limit , the molecules exert strong attractive force . This is called surface adhesion , to overcome which additional force is required . Hence frictional force increases .A. If both A and R are true and R is the correct explanation of A .B. If both A and R are true but R is not correct explanation of A .C. If A is false but R is false .D. If A is false but R is true