Download 8th Grade

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Fictitious force wikipedia , lookup

Artificial gravity wikipedia , lookup

Centrifugal force wikipedia , lookup

Gravity wikipedia , lookup

Weightlessness wikipedia , lookup

Inertia wikipedia , lookup

Centripetal force wikipedia , lookup

Free fall wikipedia , lookup

Transcript
Slide 1 / 40
Slide 2 / 40
8th Grade
Forces and Motion
Study Guide
www.njctl.org
1
A snail travels 10 m in 3000 seconds. What is the
snail's average speed?
A
60000 m/s
B
0.02 m/s
C
600 m/s
D
0.003 m/s
Slide 3 / 40
2
2
A
60000 m/s
B
0.02 m/s
C
600 m/s
D
0.003 m/s
Answer
A snail travels 10 m in 3000 seconds. What is the
snail's average speed?
D
A blimp travels at 3 m/s for 1000 s. What distance
does the blimp cover in that time?
A
500 m/s
B
3000 m
C
4500 m/s
D
500 m
A blimp travels at 3 m/s for 1000 s. What distance
does the blimp cover in that time?
A
500 m/s
B
3000 m
C
4500 m/s
D
500 m
Slide 3 (Answer) / 40
[This object is a pull
tab]
Answer
1
B
[This object is a pull
tab]
Slide 4 / 40
Slide 4 (Answer) / 40
3
When your teacher times your mile run at 8.2
minutes, that means your speed was 0.12 mi/min.
Was this your average speed or your instantaneous
speed?
Slide 5 / 40
A Average Speed
B Instantaneous Speed
3
When your teacher times your mile run at 8.2
minutes, that means your speed was 0.12 mi/min.
Was this your average speed or your instantaneous
speed?
Answer
A Average Speed
Slide 5 (Answer) / 40
avg speed =
B Instantaneous Speed
8.2mi/min
[This object is a pull
tab]
4
Does a speedometer measure the average speed or
the instantaneous speed?
A Average Speed
B Instantaneous Speed
Slide 6 / 40
4
Does a speedometer measure the average speed or
the instantaneous speed?
Slide 6 (Answer) / 40
B Instantaneous Speed
Answer
A Average Speed
Instantaneous
Speed
[This object is a pull
tab]
5 A swordfish travels for two hours. The first hour he
covers 110 kilometers, and the second hour he
covers 110 kilometers. What is the average speed of
the swordfish?
A
55 km/h
B
84 km/h
C
110 km/h
D
194 km/h
Hint: Remember
that average speed
is total distance
travelled divided by
total time
5 A swordfish travels for two hours. The first hour he
covers 110 kilometers, and the second hour he
covers 110 kilometers. What is the average speed of
the swordfish?
55 km/h
B
84 km/h
C
110 km/h
D
194 km/h
Hint: Remember
that average speed
is total distance
travelled divided by
total time
Answer
A
Slide 7 / 40
C
[This object is a pull
tab]
Slide 7 (Answer) / 40
6 A dog walks outside to go the bathroom every day. If
she walks outside at a speed of 3 meters per second
and walks 150 meters before she uses the bathroom,
how long does it take her?
A
50 seconds
B
2 minutes
C
188 seconds
D
90 seconds
A
50 seconds
B
2 minutes
C
188 seconds
D
90 seconds
Answer
6 A dog walks outside to go the bathroom every day. If
she walks outside at a speed of 3 meters per second
and walks 150 meters before she uses the bathroom,
how long does it take her?
Slide 8 / 40
Slide 8 (Answer) / 40
A
[This object is a pull
tab]
7 Carlos and Gina are riding on their horses to go into
town. They travel 140 meters in 14 seconds going
west. What is their velocity?
A
B
C
D
490 m/s west
10 m/s west
490 m/s
10 m/s
Slide 9 / 40
7 Carlos and Gina are riding on their horses to go into
town. They travel 140 meters in 14 seconds going
west. What is their velocity?
490 m/s west
10 m/s west
490 m/s
10 m/s
Answer
A
B
C
D
Slide 9 (Answer) / 40
B
[This object is a pull
tab]
8 A car travels 200 km/h west for 2 hours. The car then
travels 150 km/h east for one hour. What is the car's
position relative to its starting position?
A
50 km west
B
150 km west
C
250 km west
D
50 km east
A
50 km west
B
150 km west
C
250 km west
D
50 km east
Answer
8 A car travels 200 km/h west for 2 hours. The car then
travels 150 km/h east for one hour. What is the car's
position relative to its starting position?
C
[This object is a pull
tab]
Slide 10 / 40
Slide 10 (Answer) / 40
9
A nitro-methane powered top fuel dragster
launches from rest to race against an opponent.
Why did the car accelerate?
A
increased speed
B
decreased speed
C
changed direction
A nitro-methane powered top fuel dragster
launches from rest to race against an opponent.
Why did the car accelerate?
A
increased speed
B
decreased speed
C
changed direction
Answer
9
Slide 11 / 40
Slide 11 (Answer) / 40
A
[This object is a pull
tab]
10
A driver hits the brakes to slow down at an
intersection. As the car's speed is decreasing it has
A positive acceleration
B negative acceleration
C no acceleration
D more information is needed
Slide 12 / 40
10
A driver hits the brakes to slow down at an
intersection. As the car's speed is decreasing it has
Slide 12 (Answer) / 40
A positive acceleration
B
Answer
B negative acceleration
C no acceleration
[This object is a pull
tab]
D more information is needed
D
Time (s)
x
Y
Time (s)
Speed (m/s)
Time (s)
Y
Answer
C
x
D
Time (s)
x
Y
Speed (m/s)
Speed (m/s)
Time (s)
Slide 13 / 40
x
x
Which of the following graphs depicts the
acceleration of a runner speeding up to pass
someone.
Y
Y
B
A
Speed (m/s)
11
Time (s)
Y
Speed (m/s)
C
x
Speed (m/s)
Time (s)
Speed (m/s)
Which of the following graphs depicts the
acceleration of a runner speeding up to pass
someone.
Y
Y
B
A
Speed (m/s)
11
x
C
[This object is a pull
tab]
Time (s)
x
Slide 13 (Answer) / 40
12 Which of the following speed vs time graphs
corresponds to the position vs time graph shown in
the graph below?
Slide 14 / 40
A
B
C
12 Which of the following speed vs time graphs
corresponds to the position vs time graph shown in
the graph below?
Slide 14 (Answer) / 40
Answer
A
A
B
[This object is a pull
tab]
C
13 A ball is traveling down a hill at 4 m/s. If the ball
increases in speed to 8 m/s in 4 seconds, what is the
acceleration of the ball?
A
4 m/s
B
4 m/s/s
C
1 m/s
D
1 m/s/s
Slide 15 / 40
A
4 m/s
B
4 m/s/s
C
1 m/s
D
1 m/s/s
Answer
13 A ball is traveling down a hill at 4 m/s. If the ball
increases in speed to 8 m/s in 4 seconds, what is the
acceleration of the ball?
Slide 15 (Answer) / 40
D
[This object is a pull
tab]
14 Forces are all around us. Which of the following
do you think are examples of forces? (choose all
that apply)
A
Gravity
B
Friction
C
Muscles
D
Wind
A
Gravity
B
Friction
C
Muscles
D
Wind
Answer
14 Forces are all around us. Which of the following
do you think are examples of forces? (choose all
that apply)
A&B
[This object is a pull
tab]
Slide 16 / 40
Slide 16 (Answer) / 40
Slide 17 / 40
15 What is the SI unit for force?
A Pounds
B Kilograms
C Newtons
Slide 17 (Answer) / 40
15 What is the SI unit for force?
B Kilograms
C Newtons
Answer
A Pounds
C
[This object is a pull
tab]
16
A +20 N force acts on a car and at the same time,
a -30 N force acts on the car. What is the net
force acting on the car and is it balanced?
A
-30 N unbalanced
B
-10 N unbalanced
C
-10 N balanced
D
+ 30 balanced
Slide 18 / 40
A +20 N force acts on a car and at the same time,
a -30 N force acts on the car. What is the net
force acting on the car and is it balanced?
A
-30 N unbalanced
B
-10 N unbalanced
C
-10 N balanced
Answer
16
Slide 18 (Answer) / 40
B
[This object is a pull
tab]
D
17
+ 30 balanced
The force of gravitation between an object and a
planet is increased as they move away from each
other:
Slide 19 / 40
True
False
The force of gravitation between an object and a
planet is increased as they move away from each
other:
True
False
Answer
17
False
[This object is a pull
tab]
Slide 19 (Answer) / 40
18
Slide 20 / 40
A 100 kg kid is on the moon, where g = 1.67 m/s .
What is the boy's weight?
2
A 83.5 kg
B 167 kg
C 167 N
D 29.9 N
18
Slide 20 (Answer) / 40
A 100 kg kid is on the moon, where g = 1.67 m/s .
What is the boy's weight?
2
A 83.5 kg
C 167 N
Answer
B 167 kg
C
D 29.9 N
[This object is a pull
tab]
Slide 21 / 40
19 What is the net force acting on the object below?
-10 N
7N
-8 N
Slide 21 (Answer) / 40
19 What is the net force acting on the object below?
7N
Answer
-10 N
-11 N
[This object is a pull
tab]
-8 N
Slide 22 / 40
20 Is the object in equilibrium?
Yes
No
-10 N
7N
-8 N
Slide 22 (Answer) / 40
20 Is the object in equilibrium?
Yes
No
7N
Answer
-10 N
No
[This object is a pull
tab]
-8 N
21 What is the net force acting on the object below?
Slide 23 / 40
-10 N
25 N
-15N
21 What is the net force acting on the object below?
Slide 23 (Answer) / 40
25 N
Answer
-10 N
0N
[This object is a pull
tab]
-15N
Slide 24 / 40
22 Is the object in equilibrium?
Yes
No
-10 N
25 N
-15N
Slide 24 (Answer) / 40
22 Is the object in equilibrium?
Yes
No
25 N
Answer
-10 N
Yes
[This object is a pull
tab]
-15N
Slide 25 / 40
23 Acceleration due to gravity on Jupiter is 26.1 m/s2 .
How much would a 25 kg person weigh on Jupiter?
Slide 25 (Answer) / 40
Answer
23 Acceleration due to gravity on Jupiter is 26.1 m/s2 .
How much would a 25 kg person weigh on Jupiter?
653 N
[This object is a pull
tab]
Slide 26 / 40
24 Acceleration due to gravity on Earth's Moon is
1.67 m/s2 . How much would a 113 kg person
weigh on Earth's Moon?
Slide 26 (Answer) / 40
24 Acceleration due to gravity on Earth's Moon is
Answer
1.67 m/s2 . How much would a 113 kg person
weigh on Earth's Moon?
189 N
[This object is a pull
tab]
25
Inertia is the reluctance any material object has
to change its state of motion.
True
False
Slide 27 / 40
Inertia is the reluctance any material object has
to change its state of motion.
True
False
Answer
25
Slide 27 (Answer) / 40
True
[This object is a pull
tab]
26
Slide 28 / 40
The law of inertia applies to:
A
moving objects
B
nonmoving objects
C
both moving and nonmoving objects
Slide 28 (Answer) / 40
The law of inertia applies to:
A
moving objects
B
nonmoving objects
C
both moving and nonmoving objects
Answer
26
C
[This object is a pull
tab]
Slide 29 / 40
27 Which object has the greatest inertia?
A
Car
B
Tennis Ball
C
Freight Train
Slide 29 (Answer) / 40
28
A
Car
B
Tennis Ball
C
Freight Train
Answer
27 Which object has the greatest inertia?
C
[This object is a pull
tab]
A ball will accelerate and increase its velocity
when it feels an unbalanced force.
True
False
Slide 30 / 40
28
A ball will accelerate and increase its velocity
when it feels an unbalanced force.
Slide 30 (Answer) / 40
False
Answer
True
True
[This object is a pull
tab]
29
When the force acting on an object decreases,
the resulting acceleration will:
A
remain constant
B
increase
C
decrease
When the force acting on an object decreases,
the resulting acceleration will:
A
remain constant
B
increase
C
decrease
Answer
29
C
[This object is a pull
tab]
Slide 31 / 40
Slide 31 (Answer) / 40
30
When an object's mass is decreased but the
applied force stays the same, the resulting
acceleration will:
A
remain constant
B
increase
C
decrease
When an object's mass is decreased but the
applied force stays the same, the resulting
acceleration will:
A
remain constant
B
increase
C
decrease
Answer
30
[This object is a pull
tab]
force of 40 N and accelerate at a rate of 0.4 m/s2 .
What is the total mass of the bicycle and you?
75 kg
B
100 kg
C
120 kg
Slide 32 (Answer) / 40
B
31 You are riding your bicycle to the park to
meet a few friends. As you ride, you apply a
A
Slide 32 / 40
Slide 33 / 40
31 You are riding your bicycle to the park to
meet a few friends. As you ride, you apply a
Slide 33 (Answer) / 40
Answer
force of 40 N and accelerate at a rate of 0.4 m/s2 .
What is the total mass of the bicycle and you?
32
A
75 kg
B
100 kg
C
120 kg
B
[This object is a pull
tab]
When you sit on a chair, the chair pushes back
with force equal to your weight.
Slide 34 / 40
True
False
When you sit on a chair, the chair pushes back
with force equal to your weight.
True
False
Answer
32
True
[This object is a pull
tab]
Slide 34 (Answer) / 40
33 Which of the following statements pertains to the
third law of motion?
A
Action and Reaction pairs always act on
the same object.
B
Mass is indirectly proportional to acceleration.
C
An object at rest will remain at rest unless
acted on by an unbalanced force.
D
If a force occurs, action reaction forces are
present.
33 Which of the following statements pertains to the
third law of motion?
34
Action and Reaction pairs always act on
the same object.
B
Mass is indirectly proportional to acceleration.
C
An object at rest will remain at rest unless
acted on by an unbalanced force.
D
If a force occurs, action reaction forces are
present.
Answer
A
Slide 35 / 40
Slide 35 (Answer) / 40
D
[This object is a pull
tab]
How can a small toy have the same momentum as
a large car?
A
toy has large speed
B
both car and toy are at rest
C
toy has no mass
D
A&B
Slide 36 / 40
35
35
How can a small toy have the same momentum as
a large car?
toy has large speed
B
both car and toy are at rest
C
toy has no mass
D
A&B
Answer
A
D
If a 3 kg toy truck is moving at 4 m/s, what is the
toy's momentum?
A
3 m/s
B
2 kgm/s
C
12 kgm/s
D
12 m/s
If a 3 kg toy truck is moving at 4 m/s, what is the
toy's momentum?
A
3 m/s
B
2 kgm/s
C
12 kgm/s
D
12 m/s
Slide 36 (Answer) / 40
[This object is a pull
tab]
Answer
34
C
[This object is a pull
tab]
Slide 37 / 40
Slide 37 (Answer) / 40
36 What two factors does momentum depend on?
A
mass and volume
B
mass and acceleration
Slide 38 / 40
C mass and velocity
D mass and force
A
mass and volume
B
mass and acceleration
C mass and velocity
D mass and force
Answer
36 What two factors does momentum depend on?
Slide 38 (Answer) / 40
C
[This object is a pull
tab]
37
The law of conservation of momentum states that
the total momentum after a collision increases
from its value before the collision.
True
False
Slide 39 / 40
37
The law of conservation of momentum states that
the total momentum after a collision increases
from its value before the collision.
Slide 39 (Answer) / 40
Answer
True
False
False
[This object is a pull
tab]
38 According to Newton's 3rd law, action reaction
pairs are equal and opposite to each other. Why do
these paired forces sometimes cause different
motions if they are equal?
Answer
38 According to Newton's 3rd law, action reaction
pairs are equal and opposite to each other. Why do
these paired forces sometimes cause different
motions if they are equal?
because they
act on different
objects
[This object is a pull
tab]
Slide 40 / 40
Slide 40 (Answer) / 40