Question

A 7. 0 kg object is acted on by two forces. One of the forces is 10. 0 n acting toward the east. Which of the following forces is the other if the acceleration of the object is 1. 0 m/s² toward the east?.

Answer 1

By Newton's second law, the net force on the object is

∑ F = 10.0 N + F = (7.0 kg) (1.0 m/s²)

where F is the unknown force. Since the object is accelerating to the east, F must be acting in the same or opposite direction as the known force that is also directed eastward. Solve for F :

10.0 N + F = 7.0 N

⇒ F = - 3.0 N

which is to say, F has magnitude 3.0 N and points toward the west.