Download Force Test – Answer Key

Integrated Science
Force Test
Name: ___Answer Key_________________
For multiple-choice, please circle the correct letter. For short answer, be sure to use complete sentences and
lots of details. To get full credit, you must show your work on any problems that require calculations!
1. What is the definition of magnitude? (1 pt)
a) A force that opposes the motion of objects that touch as they move past each other.
b) Containing terms of which an increase in one results in a decrease in the other.
c) The overall force acting on an object after all the forces are combined.
d) Size, extent, dimensions.
2. What is the definition of inverse? (1 pt)
a) Containing terms of which an increase in one results in a decrease in the other.
b) The result of a force distributed over an area.
c) Containing terms of which an increase in one results in a greater increase in the other.
d) A lack or shortage; a loss.
3. What is the definition of velocity? (1 pt)
a) The amount of space taken up by an object.
b) An attractive force that acts between any two masses.
c) Speed in a given direction. It is a vector quantity.
d) The difference in position between a final position and an initial position.
4. What is the definition of pressure? (1 pt)
a) A push or a pull that acts on an object.
b) The result of a force distributed over an area.
c) The force of gravity acting on an object.
d) The constant velocity of a falling object when the force of air resistance equals the force of gravity.
5. What keeps particles in a nucleus together? (1 pt)
a) Strong nuclear force
b) Repulsion
c) Electrical force
d) Gravitational force
6. This is the weakest force but it acts over an infinite distance. (1 pt)
a) Magnetic
b) Gravitational
c) Strong nuclear
d) Electromagnetic
7. Which force allows for nuclear fusion in a star? (1 pt)
a) Magnetic
b) Weak nuclear
c) Strong nuclear
d) Electromagnetic
8. This is the force that is responsible for light. (1 pt)
a) Magnetic
b) Weak nuclear
c) Strong nuclear
d) Electromagnetic
9. Why does strong nuclear force need to be the strongest force? (1 pt)
a) Because otherwise gravitational force would cause the planets to stick together.
b) Because otherwise weak nuclear force would cause all the electrons to be emitted.
c) Because otherwise the electromagnetic force would cause the nucleus to fly apart.
d) Because otherwise magnetism would not exist.
10. The moon’s gravity is only one sixth that of Earth’s. Explain how the weight and mass of an object differ
between the two locations. (2 pts)
Mass would be the same in the two locations. Weight would be less on the moon because it has less
gravitational pull.
11. Which of the following two examples would have more gravitational force? (1 pt)
a)
2,000 kg
b)
5,000 kg
5 km
5 km
2,000 kg
5,000 kg
c) They would have the same gravitational force.
d) It is impossible to tell.
12. Which of the following two examples would have more gravitational force? (1 pt)
a)
2,000 kg
b)
2,000 kg
10 km
5 km
2,000 kg
2,000 kg
c) They would have the same gravitational force.
d) It is impossible to tell.
13. The SI unit of pressure is the (1 pt)
a) Newton
b) Pascal
c) psi
d) Joule
14. Increasing which variable would decrease the pressure of a contained gas? (1 pt)
a) Temperature
b) Volume
c) Mass
d) Joules
15. As the temperature of a gas increases, its kinetic energy (1 pt)
a) Increases
b) Decreases
c) Stays the same
d) Depends on the type of gas
16. Fill out the following table based on the combined gas law. (2 pts)
Gas
Pressure 1
(atm)
Volume 1
(L)
Temperature 1
(K)
Pressure 2
(atm)
Volume 2
(L)
Temperature 2
(K)
A
10
100
273
18.2
75
373
B
100
5
373
75
4.9
273
C
10
50
273
20
25
273.0
D
50
14.3
400
25
25
350
17. In Earth’s atmosphere, pressure and temperature both decrease as altitude increases. Weather balloons
expand as they rise. Which has more effect on the weather balloon, the decrease in pressure or the decrease
in temperature? Explain your answer. (2 pts)
As temperature decreases, volume should decrease. However, as pressure decreases, volume should
increase. Therefore, the decrease in pressure has a greater affect because the volume increases.
18. Using the following table, graph the relationship between volume and pressure. Pressure is considered the
dependent variable. Remember to label your axis! (4 pts)
Volume (m3)
Pressure (atm)
50
1000
100
500
150
333
200
250
250
200
300
167
350
143
400
125
450
111
500
100
Boyle's Law
1000
900
800
Pressure (atm)
700
600
500
400
300
200
100
0
0
25
50
75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500
Volume (m3)
Use the graph below to answer questions 19 and 20.
Gas Characteristics
100
90
80
Volume (L)
70
60
50
Gas A
40
Gas B
Gas C
30
20
10
0
-200
-150
-100
-50
0
50
100
150
200
250
300
Temperature (deg C)
19. Which of the following statements is true? (1 pt)
a) Gas A had the greatest increase in volume.
b) Gas B had the greatest increase in volume.
c) Gas C has the greatest increase in volume.
d) All the gases had the same increase in volume.
20. Approximately what temperature is gas B when it has a volume of 40 L? __190 ⁰C____ (1 pt)
21. What is an electromagnet? (1 pt)
An electromagnet is a type of magnet that is produced by the flow of an electric current.
22. Give two examples of where you might find an electromagnet in your home. (2 pts)
Doorbell, washer, dryer, refrigerator, speakers…
23. What makes an electromagnet useful? (1 pt)
a) It has a north and a south pole.
b) It can be turned on and off.
c) It can measure whether something is metal or not.
d) It does not need a source of power.
24. Which change occurs in an electric generator? (1 pt)
a) Electrical energy to mechanical energy.
b) Thermal energy to wind energy.
c) Mechanical energy to electrical energy.
d) Nuclear energy to thermal energy.
25. Which change occurs in an electric motor? (1 pt)
a) Electrical energy to mechanical energy.
b) Thermal energy to wind energy.
c) Mechanical energy to electrical energy.
d) Nuclear energy to thermal energy.
26. Two generators are identical except for the loops of wire that rotate through their magnetic fields. One has
twice as many turns of wire as the other one does. Which generator would produce the most electric
current? Why? (2 pts)
The generator with twice as many coils would produce the most electricity because the amount of electricity
generated increases as the number of coils increases.
Use the diagram below to answer the following two questions. The diagram below shows a model of a simple
electrical generator.
• There are conducting pieces that allow the circuit to remain closed as the handle is turned.
• The bulb can be lit as current electricity is produced in the wires when the handle turns the metal coil.
27. What do the pieces labeled “X” represent? (1 pt)
The pieces labeled “X” represent the permanent magnet.
28. Describe how an electrical current is produced when the coil is turned. (2 pts)
When the coil is turned, the magnets cause movement in the electrons within the coil. The movement of
electrons causes an electric current.
Use the diagram below to answer questions 29 and 30.
E
A
D
B
C
29. If A = 60 N, B = 20 N, C = 30 N, D = 30 N, and E = 30 N, what is the net force on the object? (1 pts)
The net force on the object is 50 N to the right.
30. If all of the other forces remain the same, what does the force of D need to be for the net force to be zero?
(1 pt)
The force of D needs to be 80N.
31. Use a vector diagram to show the result of a force that is 20 N to the east and a force that is 10 N to the
north. Be sure to list your scale! (3 pts)
N
10 N
20 N
Scale: 1 box = 5 N
Resultant force vector: 22.4 N to the northeast
32. Convert 3800 g/cm3 to kg/cm3. (2 pts)
I can walk 10 miles in 250 minutes. What is my speed in m/s? Round to nearest tenth. (2 pts)
33. What is the purpose of an experiment? (1 pt)
a) To communicate data
b) To test a hypothesis
c) To prove a scientific law
d) None of the above
35. When the ratio of two variables is constant, their relationship can be described as (1 pt)
a) Inversely proportional
b) Interdependent
c) Linear
d) Parallel
36. In a controlled experiment, (1 pt)
a) There are multiple responding variables
b) The responding variable is kept constant
c) The manipulated variable is kept constant.
d) Only one variable at a time is deliberately changed.
37. In an experiment, what is the difference between the results and the conclusions? (1 pt)
The results summarize the observations. The conclusions connect the results back to the hypothesis.
Conversion Factors:
100 cm = 1 m
1 mile = 1.61 km
Challenge questions (Extra credit 1% each. You must show your work!)
1. Carpet is on sale at Store A for $25/yd2 with an installation cost of $100. The same carpet is on sale at
Store B for $3.00/ft2 with an installation cost of $50. Graph the relationship between cost and area of
the room for the two carpets. Based on the graph, at what area do the carpets cost the same amount?
Calculate the cost for each carpet at that area to verify your answer.
1000
950
900
850
800
750
700
650
Cost ($)
600
550
500
Store A
450
Store B
400
350
300
250
200
150
100
50
0
0
20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380
Area (ft2)
The carpets will cost the same at ~230 ft2.
Cost at Store A = $2.78/ft2 x 230 ft2 + $100 = $739.40
Cost at Store B = $3.00/ft2 x 230 ft2 + $50=$740.00
2. How would you make the gravitation force of the second objects equal the gravitational force of the first
objects without changing the objects themselves? I want a quantitative answer not a qualitative one.
1st objects:
2,000 kg
5 km
5,000 kg
2nd objects:
25,000 kg
5 km
30,000 kg
G=(mass 1) times (mass 2) divided by the distance squared.
G1=(2,000 x 5,000)/52 = 400,000
G2=(25,000 x 30,000)/d2=400,000 so d2=(25,000 x 30,000)/400,000=1,875 so d=43.3
Move the second objects 43.3 km apart to make the force of gravity equal.
3. I am hiking and get lost. First I hike 5 miles north. Then I hike 2 miles east. Then I hike 2.8 miles directly
northwest. Then I hike another 7.1 miles directly southwest. Finally, I hike 3 miles north. Where am I
compared to where I started? You must compute this mathematically! You must provide a scale and a
compass rose. Scale: 1 box = 1 mile, Resultant vector: √
N
=√
=√
= 7.1 miles northwest