Transcript Semester 1 Exam Review Part 2

OBJECTIVE FINAL REVIEW PART 2
1. What is force?
A push or a pull that gives energy to an
object
2. What is the unit of force?
Newton
3. What is net force?
The combination of all forces acting on an object
4. CALCULATE THE NET FORCE AND DIRECTION
OF EACH PICTURE
A
250 - 124 = 126
96 - 52 = 44
126 + 44 = 150 Down
and right
B
62 - 29 = 33
545 - 375 = 170
33 + 170 = 203 Up
and left
C
490 - 92 = 398
82 - 67 = 15
398 + 15 = 413 Up
and right
1.Motion
2.Mass
3.Velocity
4.Drag
5.Momentum
6.Gravity
7.Weight
8.Force
9.Friction
10.Inertia
11.Speed
12.Acceleration
6. USE THE FORCE TRIANGLE BELOW TO SOLVE THE
FOLLOWING PROBLEMS. BE SURE TO SHOW ALL WORK
AND UNITS.
a. What is the force needed to move a 45 kg ball
25 m/s2?
1125 N
F = _____
45 kg
M = _____
2
25
m/s
A = _____
F=MxA
45 kg x 25 m/s2
b. How much mass is needed to move a box
with 1500 N of force at 5 m/s2?
1500 N
M=F/A
F = _____
300
kg
M = _____
5 m/s2
A = _____
1500 N / 5 m/s2
c. What is the acceleration of a 2500 N bike that
is 450 kg?
A=F/M
2500 N
F = _____
kg
M = 450
_____
2500 N / 450 kg
m/s2
A =5.55
_____
7. DEFINE THE FOLLOWING OF NEWTON’S LAWS:
a. Newton’s 1st Law—
b. Newton’s 2nd Law—
c. Newton’s 3rd Law—
An object in (motion/rest) stays in
(motion/rest) unless acted upon by an
unbalanced force
An object acted on by an
unbalanced force will accelerate in the
direction of force
* Force= mass x acceleration
For every action there is an equal
but opposite reaction
STATE WHICH OF NEWTON’S LAWS—1ST, 2ND, OR 3RD
APPLIES TO THE FOLLOWING STATEMENTS.
1st
___ 8. A pencil on a table will stay there until someone picks it up.
3rd
___ 9. The skier pushes her poles back to move forward.
1st
___ 10. The reason seat belts are worn.
2nd 11. It takes more force to move a bowling ball than a baseball.
___
3rd
___ 12. A fireman turns on a hose and is knocked backwards.
2nd
___ 13. You pull your little sister around the block in a
wagon.
3rd
___ 14. An astronaut uses a jet pack to go up as gasses
are expelled out the bottom.
2nd
___ 15. After you start up your motorbike, as you give it
more gas it goes faster.
3rd
___ 16. A bird flaps his wings down to fly up.
2nd
___ 17. It is easier to push an empty cart around
Walmart than a full one.
18. DEFINE FRICTION—
The force that
opposes motion
between two
surfaces that are in
contact with each
other
19. HOW DOES FRICTION IMPACT THE
MOVEMENT OF AN OBJECT?
Friction causes a moving object to slow
down. Friction applies force in the opposite
direction of the existing path of the object
The higher the amount of friction, the more
friction exists between the two objects.
20. What is a balanced force?
The total of all forces on an object
equals zero; object's motion does not
change
21. What is an unbalanced force?
The net force on an object does not equal
zero; results in the object changing its
motion
22. TWO MEN OF EQUAL STRENGTH HAVE A TUG-OF-WAR.
DRAW THE FORCES THAT ARE ACTING ONTO THE
PICTURE.
Which man will win the tug-of-war?
Neither--exerting same force
Left or Right
ANOTHER MAN JOINS EACH END OF THE ROPE. DOES
THIS AFFECT THE RESULT OF THE TUG-OF-WAR? IF NOT,
WHY NOT?
No change--still same about of force being
exerted
24. ANOTHER MAN JOINS THE TEAM ON THE LEFT.
WHICH TEAM WILL WIN THE TUG-OF-WAR NOW?
WHY?
Team on left--they are using more
force
25. IN THE PICTURE FOR QUESTION 24 ABOVE, EACH
MAN PULLS WITH A FORCE OF 10 NEWTONS.
a. How much force do the team on the left pull
30
with? __________
Newtons
b. How much force do the team on the right pull
20
with? __________
Newtons
26. WHAT IS GRAVITY?
The force of attraction
between objects that
have mass--the size of
the pull depends on the
masses of the objects.
27. WHAT IS THE DIFFERENCE BETWEEN VELOCITY
AND SPEED?
Velocity is the speed with a direction, while
speed does not have a direction.
28. WHAT IS THE DIFFERENCE BETWEEN
VELOCITY AND ACCELERATION?
Velocity is a measure of speed at any one
instant. Acceleration is a measure of change in
speed or direction.
29. WHAT INFORMATION DOES ONE NEED TO
CALCULATE VELOCITY?
Divide your distance traveled by the time it took
to travel that distance and you add your direction
to it
30. USE THE FORCE TRIANGLE TO SOLVE THE
FOLLOWING PROBLEMS. BE SURE TO SHOW ALL
WORK AND UNITS.
a. What is the speed of a skater that is going
S=D/T
80 m in 5 s?
16 m / s
S = ____
80 m
80 m / 5 s
D = ____
5s
T = ____
b. How long does it take a person jogging 9 km/hr to go
80 km?
T = D/S
9 km/hr
S = ____
80 km
D = ____
80 km /9 km/hr
8.88 hr
T = ____
c. How far does a baby crawl if it goes 2.5 m/s in 7 s?
2.5 m/s
S = ____
D=TxS
17.5 m
D = ____
7 s x 2.5 m/s
7s
T = ____
31. MATCH THE PART OF THE GRAPH TO THE
DESCRIPTION:
A
Quick acceleration: ____
D
Steady deceleration: ____
C
Gradual acceleration: ____
B
Steady speed: ____
32. MATCH THE PART OF THE GRAPH TO THE
DESCRIPTION:
Stationary: C
____
B
Increasing speed: ____
D
Slow & constant speed: ____
A
Fast & constant speed: ____
E
Returning to start: ____