Question

A 800 N crate is being pulled across a level floor by a force F of 320 N at an angle of 29° above the horizontal. The coefficient of kinetic friction between the crate and the floor is 0.25. Find the magnitude of the acceleration of the crate.

Answer 1

first, find the vertical force.
320sin29


So the net normal force on the floor is
800-320sin29

Multiply that by the coefficant of friction, .25, and you have the friction force.

Now find the net horizontal accelerating force:
320cos29-forcefrictionabove.

set that equal to ma, and solve for acceleration a.