In the diagram, a force of 20 newtons is applied to a block. The block is in dynamic equilibrium. What is the magnitude and direction of the frictional force?

Question

aliqanber · Answer

Since the block is in dynamic equilibrium (it's not moving), the force of friction is equal to the applied force but opposite in direction, to keep it from moving.

hurgleman · Answer

To elaborate on aliqanber's reply, the result would be the frictional force would be -20 newtons.

If you have F = 20 newtons, Fr = friction, and F + Fr = 0, then -F = Fr.
This only works in a single axis diagram.

sabrina.pizana · Answer

thank you guys

smoothini · Answer

20 newtons opposite to the direction of the applied force