1. Chapter 4 Test Review

2. Displacement, velocity, acceleration and force
are vectors.
Vectors are represented by arrows, the length
being the magnitude, the direction as indicated

3. The unit of force is the Newton (N)
a newton is a kg(m/s2)
mass
acceleration
Force is a push or pull, such as pushing on a
wall, or gravity pulling you down (weight)

4. SF = ma mass = 10 kg What is the force of gravity pulling down on this
ball? (10 extra credit points to whoever shouts out
the correct answer first…)
What is the net force if there is 10 N of air
resistance opposing the fall (10 points to
somebody else…)

5. Newton’s Third Law of Motion
For every action force, there is an equal
and opposite reaction force…
10 N
10 N

6. If there is no acceleration (constant
velocity), there is no net force. Forces
left = forces right. Forces up = forces
down.
80 m/s

7. A baseball player hits a baseball. What forces
are acting on the baseball, after the hit?
friction ?
(we’ll ignore air
resistance)
b. the force of the hit ?
c. the normal ?
d. gravity ?
e. tension ?

8. Friction is f = mN 100 Kg pulled with a force of 10 N
at a constant speed of 5 m/s
What if the force of friction?
What is the normal force?
What is the coefficient of friction?

9. Label all of the forces
Fp (T) N
Fpy f
Fpx mg

10. Box sliding down an inclined plane…
label the forces
Which force pushes the box down the slope? N f F┴ mg
FII

11. Label the forces…
Fp (T)
Fpy N
Fpx f F┴ mg
FII

12. hangs from three ropes. What is the tension in the middle rope?
A ball with a mass of 20 Kg
hangs from three ropes. What
is the tension in the middle
rope? T2
T1 = 30 N
T3 = 50 N
q1 = 85°
q3 = 42°
mg = 20 Kg (9.81 m/s2)
= N
sin 85° (30N) + sin 42° (50N) + T2 = 196.2N
T2 = 196.2N - sin 85° (30N) - sin 42° (50N)
T2 = 132.8N