Please help me with these questions from the Science 6: Forces and Motions Unit Test.
My answer-******
1. Which of the following best describes the movement of an object at rest if no outside forces act on it? (1 point)
It will move due to inertia.
Gravity will eventually cause it to move.
It will stay at rest due to inertia. *****
It will stay at rest due to gravity.
2. A 2,500 kg car moves south at 15 m/s2; 15 m/s2 south is the ___________ of the car. (1 point)
acceleration****
displacement
velocity
speed
3. Two people are pushing a couch from opposite sides. One person is pushing to the right with a force of 3 N. The other person is pushing to the left with a force of 4 N. Which of the following best describes the movement of the couch? (1 point)
The couch will move to the left with a force of 1 N.*******
The couch will not move.
The couch will move to the right with a force of 7 N.
The couch will move to the left with a force of 7 N.
4. Which of the following is true of an object in a circular motion at a constant speed? (1 point)
The net force on the object is zero.
The object is not accelerating as the speed of the object remains the same.
The object is accelerating as the direction of object is changing.*****
The object is accelerating as the velocity remains the same.
5. If a bowling ball hits a wall with a force of 6 N, the wall exerts a force of ____ back on the bowling ball. (1 point)
0 N**********
3 N
6 N
12 N
6. A person roller skates down a street heading east. Which of the following would be true about friction in this scenario? (1 point)
Friction does not affect the skates in this scenario.********
Friction pulls the skates’ wheels eastward.
Friction pulls the skates’ wheels downward, toward the center of Earth.
Friction pulls the skates’ wheels westward.
7. Which type of measurement does the following sentence describe?
A robin flies east at 15 meters per second. (1 point)
velocity****
distance
acceleration
displacement
8. As a raindrop falls from a cloud to the surface of Earth, (1 point)
its speed increases due to gravity.
its speed increases due to air resistance.
it moves at a constant speed.
it moves at a constant velocity.******************
9. Ball A and Ball B are rolled so that they will collide. Does the data in the table below demonstrate the law of conservation of momentum?
Ball A Momentum Before Collision
Ball B Momentum Before Collision
Total Momentum of Both Balls After Collision
3 kg m/s
2 kg m/s
6 kg m/s
(1 point)
Yes, because the total momentums before and after the collision are equal.
Yes, because the total momentums before and after the collision are unequal.******
No, because the total momentums before and after the collision are equal.
No, because the total momentums before and after the collision are unequal.
10. Which of the following best describes the motion of a rolling soccer ball during a game? (1 point)
It will not be affected by inertia.*****
It will have a constant velocity until acted upon by outside forces.
It will not be affected by gravity.
It will have a constant velocity due to outside forces.
11. A 5 kg skateboard moves at 7 m/s2. What is the force of the skateboard? (1 point)
2 m/s2
12
7 m/s******
35 N
12. Which of the following does not change when a car keeps a constant speed but changes direction? (1 point)
acceleration
velocity*****
momentum
mass
13. Which of the following is not a force that would act on a skateboard rolling down a ramp? (1 point)
gravity*****
air resistance
rolling friction
static friction
14. Two people are pushing a couch from the same side. One person pushes with a force of 2 N. The other person pushes with a force of 4 N. Which of the following best describes how the couch will move? (1 point)
The couch will move with a force of 8 N.******
The couch will move with a force of 2 N.
The couch will not move.
The couch will move with a force of 6 N.
15. A book is sitting on a table. Which of the following is true about the table? (1 point)
It is pushing up on the book.
It exerts no force on the book at all.******
It is pulling down on the book.
It can affect the mass of the book.
16. Which of the following is the outside force that causes the planet Jupiter to orbit the sun? (1 point)
sliding friction
gravity*****
air resistance
mass
17.
In the diagram above, the arrows represent momentum. A larger arrow indicates more momentum. Which of the following best describes how the balls will move after ball A collides with ball B? (1 point)
Ball A will bounce off of ball B and roll to the left, and ball B will continue to roll to the right.
Both balls will roll to the left.****
Ball A will stop moving, and ball B will continue to roll to the right.
Both balls will roll to the right.
18. Why does a car slide when it rolls over an icy patch on a road? (1 point)
Cars have more momentum on icy surfaces.****
There is less friction between the car tires and the ice than between the car tires and the road.
There is more friction between the car tires and the ice than between the car tires and the road.
Cars have less momentum on icy surfaces.
19. How would the woman in the image below know if the plane she is watching was moving?
(1 point)
She could use the plane as a reference point.***********
She could use the building behind the plane as a reference point.
She could use the clouds in the sky as reference points.
She could use other moving planes as reference points.
20. If the net force acting on an object is 0 N, the forces are (1 point)
balanced.
unbalanced.************
not present.
a result of friction.
21. If you swung a bucket of water quickly in an upside down circular path, the water would not fall out of the bucket. Which of the following best describes why this happens? (1 point)
Due to centripetal force, the water is pushing on the bottom of the bucket.************
Air resistance pushes on the water and keeps it from falling out.
Gravity does not act on objects moving in a circular path.
The collisions between the water and the sides of the bucket keep the water from falling out.
22. An object has more momentum if it has which of the following? (1 point)
a large mass and low velocity
a high velocity and small mass**********
a high velocity and large mass
a low velocity and small mass
23. A scientist from the United States conducts an experiment using miles per hour to measure speed. Why might this be confusing for scientists in other countries? (1 point)
Scientists in other countries don’t usually perform experiments involving speed.
Scientists in other countries express speed as mass times acceleration.
Scientists in other countries use SI units when measuring speed.*****
Scientists in other countries do not use SI units when measuring speed.
Open ended Questions:
24.
Use Newton’s first law of motion to explain how wearing a seat belt in a moving car could help prevent injury.
25.A skydiver prepares to jump out of a plane. Explain how gravity and air resistance will affect the motion of the skydiver before and after he or she opens the parachute. (4 points)
Anyone who answers these questions, please give me the answers and explain how you got it. If not please give me clues on how to get the answers since I need help with these.
C
2.A
3.A
4.C
5.C
6.D
7.A
8.A
9.D
10.B
11.D
12.D
13.D
14.D
15.A
16.B
17.D
18.B
19.B
20.A
21.A
22.C
23.C