A crate of apples weighing 71.4 N 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. What is the interaction partner of normal force?
1. If the interaction partner is acting above the surface of the ramp, enter a positive value.
2. If the interaction partner is acting below the surface of the ramp, enter a negative value.