Posted by JAYZ on .
A 149 kg crate is pushed at constant speed up a frictionless inclined plane of $\theta$ = 51 $^{\circ}$ with the horizontal. Assuming one pushes with a horizontal force, what is the magnitude of the force F (in N) required to do this?

Physics 
Henry,
Wc = m * g = 149kg * 9.8N/kg = 1460 N. =
Wt. of the crate.
Fp = 1460*sin51 = 1135 N. = Force parallel to the plane.
Fv = 1460*cos51 = 919 N. = Force perpendicular to the plane.
FapFp = m*a
Fap1135 = m*0 = 0
Fap = 1135 N. = Force applied parallel to the plane.
Fh = Fap*cos51 = 1135*cos51 = 714.3 N. =
Required hor. force.