Question #98018

1 Answer
Jun 30, 2017

F_x = 15.3 "N"

F_y = 12.9 "N"

F_n = 6.84 "N" (normal force)

Explanation:

I'll assume the vector shown with magnitude 20 is the force, and I can't say what the unit m is, although I'll treat it as Newton's, "N".

We're asked to find the horizontal and vertical components of a force, and the force normal to the incline plane.

Components:

The force is at angle of

20^"o" + 20^"o" = 40^"o"

relative to the horizontal. It has a magnitude of 20 "N", and its components are thus

F_x = Fcostheta = (20color(white)(l)"N")(cos40^"o") = color(red)(15.3) color(red)("N"

F_y = Fsintheta = (20color(white)(l)"N")(sin40^"o") = color(blue)(12.9) color(blue)("N"

The force normal to the plane is the vertical component of the force relative to the plane, which is perpendicular to it.

It makes an angle of 20^"o" with the plane, so it's vertical component F_n is

F_n = Fsintheta = (20color(white)(l)"N")(sin20^"o") = color(green)(6.84) color(green)("N"

Thus, the force exerted normal to the incline plane has a magnitude of color(green)(6.84 sfcolor(green)("newtons".