What will be the co-efficient of static friction if a force of \(10N\) acts horizontally on a block of mass \(4kg\) resting on a horizontal surface is needed just to start the block moving over the horizontal surface. Take: \(g=10\frac{m}{s^{2}}\).
Ans: \(\mu_{s}=0.25\).
A block of mass \(1kg\) lies on a horizontal surface in a truck. the co-efficient of static friction between the block and the surface is \(0.6\). If, the acceleration of the truck is \(5\frac{m}{s^{2}}\). calculate: the frictional force acting on the block.
Ans: \(5N\).
A block of weight \(40N\) is placed on a horizontal table and tension \(T\), which can be increased to \(16N\), before the block begins to slide. A force of \(8N\) keeps the block moving at constant speed once it has been set into motion. find: the co-efficient of static and kinematic friction.
Ans:\(\mu_{s}=0.40\) and \(\mu_{k}=0.20\).
An automobile is moving on a horizontal road with a speed \(v\). If, the co-efficient of friction between the tyres and the road is \(\mu\), show that: shortest distance in which the automobile can be stopped is \(\frac{v^{2}}{2\mu g}\).
A truck is moving at a speed of \(54\frac{km}{hr}\) carries a steel girder which rest on its wooden floor. What is the minimum time in which the truck can be stopped with out the girder moving forward? Given: Co-efficient of static friction between steel girder and the wooden surface is \(0.5\).
Ans: \(t=3.06s\) .
A mass of \(4kg\) rests on a horizontal plane. the plane is now gradually inclined to an inclination angle \(\theta=15^{o}\) with the horizontal, and the mass just began to slide over the inclined surface. What is the coefficient of static friction between the blocks and the surface?
Ans: \(0.7\).
A bullet of mass \(10g\) is fired horizontally into a \(5kg\) wooden block, at rest on a horizontal surface. The co-efficient of kinetic friction between the block and the surface is \(0.1\). calculate: the speed of bullet striking the block, if the combination moves \(20m\) over the horizontal surface before coming to a stop?
Ans: \(3136.26\frac{m}{s}\).
A body weighing \(15kg\) just slides down a rough inclined plane that rises \(5m\) in every \(13m\). what is the co-efficient of friction?
Ans: \(\mu_{s}=0.416\).
What will be the acceleration of the block and trolley system shown in figure. If, the co-efficient of kinematic friction between trolley and the surface is \(0.04\)?Taking: \(g=10\frac{m}{s^{2}}\) and string is massless.
Ans: \(T=27.12N\).
A motor car is running at the rate of \(7\frac{m}{s}\) can be stopped by applying breaks in \(10m\). And also show that the total resistance offered to the motion when breaks are on , is equal to; \(\frac{1}{4}\times\left(mg\right)\). Where; mg=Weight of the Car.
A block(Block-A) of mass \(8kg\) is placed on another block(Block-B) of mass \(10kg\), and the block B rests on a smooth horizontal table. For, sliding the block A over block B, a horizontal force of \(24N\) is required to be applied on it. How much maximum horizontal force can be applied on block B so that Block A and Block B move together? Also, find out the acceleration produced by the force in combination of masses?
Ans: \(54N\) and \(3\frac{m}{s^{2}}\).
A particle of mass \(m\) rests on a horizontal floor with which it has a co-efficient of static friction is \(\mu\). It is desired to make the body move by applying minimum possible force \(F\). Find: its magnitude and direction.
Ans: \(F_{min}=\frac{\mu mg}{\sqrt{\mu^{2}+1}}\)‘
A body rolls on ice with a velocity \(8\frac{m}{s}\), comes to rest after travelling a distance of \(4m\). Calculate: the co-efficient of friction.
Ans:\(\mu=0.816\).
An engine of \(100H.P\) draws a train of mass \(200 MT\) with a velocity of \(36\frac{km}{hr}\). Find: the co-efficient of friction.
Ans:\(\mu=0.0038\).
In blow figure the masses of block A and block B are \(10Kg\) and \(5Kg\). Calculate: the minimum mass of Block C which may stop the slipping of mass A over the horizontal surface of table. Given: Co-efficient of friction between Black A and table is \(0.2\).
Ans: \(m=15 kg\).
A block of mass \(4Kg\) is placed on another block B of mass \(5Kg\) and block B rests on a horizontal table. For, sliding the block A on block B, a horizontal force of \(12N\) is required to be applied on it. How much horizontal force can be applied on block B so both A and B will move together? Also; find out the acceleration produced by this force.
Ans: \(27N\).
A horizontal force of \(10N\) is necessary to just hold a block stationary against a wall. The co-efficient of friction between the block and the wall is \(0.2\). Calculate: the weight of the block?
