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Name:_______________
Vocabulary: Write the correct word in each space.
Word Bank:
force
acceleration
friction
velocity
gravity
speed
net force
motion
1._________________ is the force that opposes motion between two objects in contact.
2. A. _________ is a push or a pull exerted on an object in order to change the object’s motion
3. ____________ is the force of attraction between two objects due to their masses and the distance
between them.
4. _____________ is the combination of all forces acting on an object.
5. _________________ is the rate at which an object moves in a given direction.
6. _________________ is the rate at which velocity changes.
7. _______________ is when an object changes position over time in relation to a reference point.
8. _________________ is the rate at which an object moves.
Friction and Gravity:
Circle the correct term in parentheses.
9. Gravity was discovered by (Sir Isaac Newton/Dmitri Mendeleev)
10. As the distance between two objects increases,
(increases/decreases).
the force of gravity between them
11. As the mass of an object increases, the force of gravity (increases/decreases).
12. A measure of gravitational force is (mass/weight). The units of measurement used are
(kilograms/Newtons).
13. A measure of the amount of matter in an object is (mass/weight). Mass is measured in units called
(kilograms/Newtons). Mass (always remains the same/changes based on gravity).
14. When a surface is rough, the friction (increases/decreases).
15. When you increase the force applied to an object, friction (increases/decreases).
16. When you make a surface smoother, friction is (increased/decreased).
17. A carpet has (more/less) friction than a hardwood floor.
19. Friction is (harmful/helpful/both harmful and helpful).
For numbers 18-25 write a “+” if the statement is an example of helpful friction and a “-“ if it is an
example of harmful friction:
_______18. Engine parts wearing out.
________19. Soil erosion.
_______20. A person walking.
________21. Car tires moving a car forward.
_______22. Brakes stopping a car.
_______23. Holes developing in your socks.
_______24. A pencil writing on paper.
_______ 25. An eraser erasing.
Forces:
Calculate the net force in each problem below. Be sure to include which direction the box will travel, and
whether it is balanced or unbalanced. If it does not move, write “none” for direction of motion.
26.
27.
70N
20N
210N
20N
70N
Net Force:________________
Net Force:________________
Direction of motion:________
Direction of motion:________
Is it balanced? ____________
Is it balanced? ____________
28.
29.
12N
642N
8N
426N
Net Force:________________
Net Force:________________
Direction of motion:________
Direction of motion:________
Is it balanced? ____________
Is it balanced? ____________
30.
31.
6.25N
40N
57N
8.5N
Net Force:________________
Net Force:________________
Direction of motion:________
Direction of motion:________
Is it balanced? ____________
Is it balanced? ____________
32.
42N 33.
15N
17N
44N
41N
Net Force:________________
Net Force:________________
Direction of motion:________
Direction of motion:________
Is it balanced? ____________
Is it balanced? ____________
34.
300N
362N
35.
800N
852N
490N
Net Force:________________
Net Force:________________
Direction of motion:________
Direction of motion:________
Is it balanced? ____________
Is it balanced? ____________
36. Circle the statements about forces that are 100% true. (hint: there are 3)
A. Force can be transferred from one object to another using motion.
B. There cannot be a force without motion.
C. If there is motion, then a force is acting.
D. Forces act on objects at rest.
E. Moving objects stop when the force is used up.
F. The stronger the force, the faster an object moves.
G. Forces make things go, losing energy makes them stop.
H. A force is necessary in order to change the direction of motion.
I. Constant speed results from constant force.
J. Objects can continue moving in a straight line without applying force.
K. If there is no motion, then there is no force acting.
37. What kind of force is required to cause an object to start moving? (balanced/unbalanced)
38. When the net force is equal to 0 N, they are (balanced/unbalanced).
39. When the net force is greater than 0N, it is (balanced/unbalanced).
40. UNITS: Write A for Acceleration. Write S for Speed. Write V for Velocity. Write F for force.
_____ A. 38 m/s/s
_____ F. 82 N
_____ K. 683 m/s/s
_____ B. 42 mi/h West
_____ G. 14 km/h
_____ L. 22 m/s South
_____ C. 182 m/s
_____ H. 38 mi/h North
_____ M. 72 N to the right
_____ D. 34 m/s North
_____ I. 68 m/s/s
_____ N. 82 mph
_____ E. 2 m/s/s
_____ J. 22 cm/s
_____ O. 2 mi/h/s
SPEED:
41. What is the formula for calculating speed?
42. Which of the following are two factors that determine speed?
A. acceleration and time
B. distance and time
C. motion and Time
D. velocity and time
41. Speed is the _________ at which an object moves.
42. A car travels around the block. It travels 16 miles in .5 hours. Its average speed is____________
43. You are driving to Savannah. It is 244 miles away and it takes you 4 hours to get there. What was
your average speed?________________
44. You are driving to Greenville, South Carolina. It is 135 miles away, and it takes you 2.5 hours. What
was your average speed?_________________
45. You are driving to Huntsville, Alabama. It takes you 2 hours to get there and you drive an average
of 60 miles per hour. How many miles away is Huntsville, Alabama?__________________
Velocity:
46. Which of the following explains the difference between speed and velocity?
A. Velocity has motion, and speed does not.
B. Velocity has direction, and speed does not.
C. Velocity involves time, and speed does not.
D. Velocity involves acceleration and speed does not.
47. Jessica jogs on a path that is 2.5 meters long to get to a park that is south of her location. It takes
her 1 hour. What is her velocity?
48. You are traveling 80 miles for a total of 1.5 hours. You are traveling north. What is your velocity?
49. A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down, its speed is
4 m/s. Then 3 seconds later; its speed is 22 m/s. What is its average acceleration?
50. A lizard accelerates from 2 m/s to 10 m/s in 4 seconds. What is the lizard’s average acceleration?
51. You are traveling in a car that is moving at a velocity of 20 m/s. Suddenly, a car 10 meters in front
of you slams on its brakes. At that moment, you also slam on your brakes and slow to 5 m/s. Calculate the
acceleration if it took 2 seconds to slow your car down.
Graphing Speed and Acceleration
Use the graph below to answer questions 52-54.
52.
During which part of the journey was the bus moving fastest?
53.
During which part of the journey did the bus have the greatest acceleration?
54.
Calculate the acceleration between D and E.
Use the graph below to answer questions 55-58.
55.
Which runner won the race?
56.
Which runner stopped for a rest?
a. Where did he stop?
b. How long did he stop?
57.
How long did Bob take to complete the race?
58.
Calculate Albert’s average speed.