An 80.0-N crate of apples sits at rest on a ramp that runs from the ground to the bed of a truck. The ramp is inclined at 20.0° to the ground.
(a) What is the normal force exerted on the crate by the ramp?
(b) The interaction partner of this normal force has what magnitude and direction? It is exerted by what object on what object? Is it a contact or a long-range force?
(c) What is the static frictional force exerted on the crate by the ramp?
(d) What is the minimum possible value of the coefficient of static friction?
(e) The normal and frictional forces are perpendicular components of the contact force exerted on the crate by the ramp. Find the magnitude and direction of the contact force.