A plank with a box on it at one end is gradually raised about the other end. As the angle of inclination with the horizontal reaches 30°, the box starts to slip and slides 4.0 m down the plank in 4.0 s. The coefficients of static and kinetic friction between the box and the plank will be, respectively:

A bus moving at a speed of 24 m/s begins to slow at a rate of 3 m/s each second. How far does it go before stopping?

A 60 kg man stands in contact against the inner wall of a hollow cylindrical drum of radius 4m rotating about its vertical axis with 180 rev./min. The coefficient of friction between the wall and his clothing is 0.20. Find the minimum rotational speed of the cylinder to enable the man to remain stuck to the wall (without falling) when the floor is suddenly removed? Assume g = 10 $$\text{m/s}^2$$​

Which of the following is the correct expression for maximum possible speed of a caron a banked road?