A 20kg block is sliding down a 30° ramp at a constant velocity. Calculate the normal force acting on the block. Calculate the coefficient of kinetic friction between the block and the ramp.

Let me try:

Normal force= 169.74N

Coefficient of kinetic friction= 0.577

Explanation

a. For a given inclined plane, normal friction is equal to the force perpendicular to the plane which is equal to

mgcos theta = 20×9.8× cos30 = 169.74N

b. The coefficient of kinetic friction for an inclined plane is given as

tan theta =tan 30 = 0.577

i think it would be 80 km/h because 30 + 50 = 80 (sorry if this not the right answer i'm trying my best)