posted by Corey .
A student, crazed by the first physics Midterm, uses a pushing force of
80 N angled at 70° to push a 5.0 kg book across the frictionless ceiling
of his room.
a. What is the block's acceleration?
b. What is the force of the ceiling on the book?
Is the force applied at 70 degrees to the ceiling or the surface normal?
I assume it is 70 degrees to the ceiling, otherwise the brick would fall. The normal force on the ceiling is then 80sin70-5g = 26.1 N
(That is the answer to part (b))
The component along the ceiling is then
80 cos70 = 27.4 N
Acceleration = 27.4 N/(mass)= 5.47 m/s^2