$A$ hockey player is moving northward and suddenly turns westward with the same speed to avoid an opponent. The force that acts on the player is

The mass of a hydrogen molecule is $3.32 \times 10^{-27} \ kg$. If $10^{23}$ hydrogen molecules strike,per second,a fixed wall of area $2 \ cm^2$ at an angle of $45^\circ$ to the normal,and rebound elastically with a speed of $10^3 \ m/s$,then the pressure on the wall is nearly:

Place a uniform meter scale horizontally on your extended index fingers with the left one at $0.00 \ cm$ and the right one at $90.00 \ cm$. When you attempt to move both fingers slowly towards the center,initially only the left finger slips with respect to the scale and the right finger does not. After some distance,the left finger stops and the right one starts slipping. Then the right finger stops at a distance $x_R$ from the center $(50.00 \ cm)$ of the scale and the left one starts slipping again. This happens because of the difference in the frictional forces on the two fingers. If the coefficients of static and dynamic friction between the fingers and the scale are $0.40$ and $0.32$,respectively,the value of $x_R$ (in $cm$) is:

The figure shows a man standing stationary with respect to a horizontal conveyor belt that is accelerating with $1 \; m/s^2$. What is the net force on the man? If the coefficient of static friction between the man's shoes and the belt is $0.2$,up to what acceleration of the belt can the man continue to be stationary relative to the belt? (Mass of the man $= 65 \; kg.)$

Among the forces in nature,friction can be classified into

$A$ $500 \, kg$ horse pulls a cart of mass $1500 \, kg$ along a level road with an acceleration of $1 \, m/s^2$. If the coefficient of sliding friction is $0.2$,then the force exerted by the horse in the forward direction is ......... $N$.