A block of mass $m$ rests on a horizontal surface with coefficient of static friction $\mu_s$. A force $F$ is applied at an angle $heta$ to the horizontal. The minimum force required to just move the block is:

Rolling friction is generally _______ than sliding friction.

A block of mass 2 kg is placed on a rough horizontal surface with coefficient of static friction 0.4. What is the minimum horizontal force required to just start moving the block?

A body of mass m is projected with a speed u making an angle $\alpha$ with the horizontal. The change in momentum suffered by the body along he y-axis between the starting point and the highest point of its path will be

A block of mass 5 kg is placed on a rough horizontal surface with a coefficient of static friction of 0.4. A horizontal force is applied to the block. What is the minimum force required to start moving the block?

A shell of mass m moving with velocity v suddenly breaks into 2 pieces. The part having mass m/4 remains stationary. The velocity of the other shell will be

An object of mass 3m splits into three equal fragments. Two fragments have velocities $v\hat j\,and\,v\hat i$ . The velocity of the third fragment is

Which of the following statements about static friction is correct?

A block of mass $m$ is placed on a horizontal surface. A force $F$ is applied horizontally to the block. If the block is just about to move, which of the following represents the force of static friction?

A bullet of mass 0.02 kg travelling horizontally with velocity $250\;m{s^{ - 1}}$ strikes a block of wood of mass 0.23 kg which rests on a rough horizontal surface. After the impact, the block and bullet move together and come to rest after travelling a distance of 40m. The coefficient of sliding friction of the rough surface is $\left( {g = 9.8\;m{s^{ - 2}}} \right)$

Which of the following statements about kinetic friction is incorrect?