1. Ch. 4 Forces

2. Explain the relationship between the motion of an object and the net force
acting on the object.
Determine the net external force on an object.
3. Calculate the force required to bring an object into equilibrium.

4. Newton’s 1st Law
An object at rest stays at rest, and an object in motion continues with constant velocity unless the object experiences an unbalanced external force

5. Newton’s 1st Law Law of Inertia Inertia
the tendency of an object not to accelerate
if the net force is zero, there is no acceleration

7. d2 = x2 + y2 opp = hyp(sinθ) adj = hyp(cosθ)
Newton’s 1st Law
d2 = x2 + y2 opp = hyp(sinθ) adj = hyp(cosθ)

8. The wind exerts a force of 7 N north while a ball rolls with a force of 12 N south. What is the net force on the ball?

9. A sailboat is traveling north with a force of 400 N
A sailboat is traveling north with a force of 400 N. The wind exerts a force of 275 N to the west. What is the magnitude and direction of the net external force on the sailboat?

10. A traveler is pulling a suitcase with a force of 70 N at an angle of 35° above the horizon. What are the horizontal and vertical components of this force?