A particle moves move on the rough horizontal ground with some initial velocity `V_(0)`. If `(3)/(4)` of its kinetic enegry lost due to friction in time `t_(0)`. The coefficient of friction between the particle and the ground is.

A aprtical moves on a rough horizontal ground with same initial velocity say v_(0) . If (3//4)th of its kinetic energy is lost in friction in time t_(0) , then coefficient of friction between the partical and the ground is:

A block begins to move on a rough horizontal surface with an initial velocity u. If it loses of its initial kinetic energy in time t, the coefficient of kinetic friction between the block and the surface is

A particle is projected directly along a rough plane of inclination theta with velocity u. If after coming to the rest the particle returns to the starting point with velocity v, the coefficient of friction between the partice and the plane is

A body moving on the ground with a velocity of 15m//s comes to rest after covering a distance of 25m If acceleration due to gravity is 10m//s^(2) Calculate the coefficient of friction between the ground and the body .

A 50 kg man is standing at the centre of a 30 kg platform A. Length of the platform is 10 m and coefficient of friction between the platform and the horizontal ground is 0.2. Man is holding one end of a light rope which is connected to a 50 kg box B. The coefficient of friction between the box and the ground is 0.5. The man pulls the rope so as to slowly move the box and ensuring that he himself does not move relative to the ground. If the shoes of the man does not slip on the platform, calculate how much time it will take for the man to fall off the platform. Assume that rope remains horizontal, and coefficient of friction between shoes and the platform is 0.6.

Asseration : A block of mass m starts moving on a rough horizontal surface with a velocity v. It stops due to friction between the block and the surface after moving through a ceratin distance. The surface is now tilted to an angle of 30^@ with the horizontal and same block is made to go up on the surface with the same initial velocity v. The decrease in the mechanical energy in the second situation is small than the first situation. Reason : The coefficient of friction between the block and the surface decreases with the increase in the angle of inclination.

A block starts moving up an inclined plane of inclination 30^@ with an initial velocity of v_0 . It comes back to its initial position with velocity (v_0)/(2) . The value of the coefficient of kinetic friction between the block and the inclined plane is close to I/(1000) , The nearest integer to I is ____________ .

A positively charged particle of mass m and charge q is projected on a rough horizontal x-y plane surface with z-axis in the vertically upward direction. Both electric and magnetic fields are acting in the region and given by vec E = - E_0 hat k and vec B= -B_0 hat k , respectively. The particle enters into the field at (a_0, 0, 0) with velocity vec v = v_0 hat j . The particle starts moving in some curved path on the plane. If the coefficient of friction between the particle and the plane is mu . Then calculate the (a) time when the particle will come to rest (b) distance travelled by the particle when it comes to rest.

A uniform ring of mass 'm' and radius 'R' is projected horizontally with velcoty v_(0) on a rough horizontal floor, so that it starts off with a purely sliding motion and it acquires a pure rolling motion after moving a distance d. If the coefficient of friction between the ground and ring is mu , then work done by the friction in the process is