Dan Ira King

1.A block of masses mA is on a plane inclined at an angle θ with the horizontal. It is attached to another mass mB by means of string that passes over a pulley at the top of the incline. For mA = 8kg, mB = 5kg, θ = 20o, and the coefficient of kinetic fric...

A box weighing 890N is pulled along a horizontal surface by means of a string which is at 30o above the horizontal. If the coefficient of kinetic friction is 0.2 and the box is accelerated at 0.8 m/s2, what is the tension in the string?

A block slides from rest from the top of a plane 8m long and inclined 35o with the horizontal. If the coefficient of friction is 0.20, find how long it will take the body to reach the bottom of the plane.

9. Two blocks connected by a cord passing over a small frictionless pulley rest on frictionless planes as shown in the figure below. (a) Which way will the system move? (b) What is the acceleration of the block? (c) What is the tension in the cord?

What happens to the coefficient of friction? Why is it not used?

I still don't get it sorry