Saturday, October 09, 2004
Practice Questions for First Big "Celebration" (Exam)
Phys Sci Practice Questions for 1st Exam: Working through these problems is an excellent way to study. Use your book and notes for answers (answers are also given at the bottom)
Short Answer:
1. Arrange each of the following in order from largest to smallest.
1. centimeter
2. kilometers
3. meters
4. micrometers
5. millimeters
2. Two cars start at the same point and drive in a straight line for 5 km. At the end of the drive their distances are the same but their displacements are different. Explain.
3. Two cars are traveling along the same road at the same speed but at different velocities. Explain.
4. A car is driving down a road. Is it possible for its position to be changing and its acceleration to be zero? Is it possible for its velocity to be changing and its acceleration to be zero?
5. A car has an acceleration of –5 m/s2. Describe the car’s motion.
6. If two equal forces act on an object in opposite directions, what is the net force? What is the acceleration?
7. Why is it necessary to wear a seat belt to hold you in place if you are riding in a car that stops suddenly?
8. Sally sits on a rock. Her weight is an action force. Describe its reaction force.
9. Explain how mass and weight are different from each other.
10. Why is your weight less on the Moon than on Earth, but your mass is the same?
11. Which body processes are fueled by chemical potential energy?
12. Is it possible for a ball to have both kinetic energy and potential energy at the same time? Explain.
13. Explain the changes in energy when a child slides down a sliding board.
14. How does the child's ride on the slide change if the slide is lubricated with water to make it slippery?
15. A dump truck, a sports car, and a bicycle are traveling at the same velocity. Compare their kinetic energies.
16. Describe how you could quickly determine whether a string of lights is wired in series or in parallel.
17. List two materials that are conductors and two materials that are insulators.
18. How is the amplitude of a compressional wave determined?
19. You shake the end of a rope to make a wave. You start shaking the rope a greater distance but at the same speed. How are the wavelength, frequency, amplitude, and speed affected?
Problems
20. A cross-country runner runs 10 km in 40 minutes. What is his average speed?
21. A high speed train travels with an average speed of 227 km/h. The train travels for 2 h. How far does the train travel?
22. Find the acceleration of a car that goes from 32 m/s to 96 m/s in 8.0 s.
23. A 10-kg wagon has a speed of 25 m/s. What is its momentum?
24. Calculate the force on an object that has a mass of 12 kg and an acceleration of 4 m/s2.
25. An 18-kg bicycle carrying a 62-kg girl is traveling at a speed of 7 m/s. What is the kinetic energy of the girl and bicycle?
26. A 70-kg boy is sitting 3 m from the ground in a tree. What is his gravitational potential energy?
27. A 90-kg ceiling light is suspended 4 m above the floor. What is its gravitational potential energy?
Phys Sci Question
Answer Section
SHORT ANSWER
1. ANS:
2, 3, 1, 5, 4
2. ANS:
The two cars drove in different directions.
3. ANS:
The two cars are traveling in different directions.
4. ANS:
Yes, it could have constant speed. No, a change in velocity is always an acceleration.
5. ANS:
The car is slowing down at the rate of 5 m/s every second.
6. ANS:
0, 0
7. ANS:
A seat belt helps to minimize injury from the inertia that keeps your body moving forward.
8. ANS:
The rock supplies an upward reaction force on Sally equal to her weight.
9. ANS:
Mass measures the amount of matter; weight measures the force of gravity on the matter.
10. ANS:
Your mass is the same because you didn't change the amount of matter, but the gravitational force decreased, decreasing your weight.
11. ANS:
heartbeat, digestion, warmth, movement
12. ANS:
a ball on a desk has potential energy; as it falls, it has both potential energy and kinetic energy
13. ANS:
At the top, he has 100% potential energy. As he slides, potential energy changes to kinetic energy and thermal energy because of friction. At the bottom of the slide his energy has transformed entirely into kinetic energy and thermal energy.
14. ANS:
Friction is decreased so more potential energy changes to kinetic energy without being lost to thermal energy. The child's ride is faster.
15. ANS:
Kinetic energy is based on mass and velocity. Given equal velocity, the dump truck has the most mass, so it has the most kinetic energy. The sports car would be next, and the bicycle last.
16. ANS:
Remove one bulb. If it's a series, all the lights will go out; if it's parallel, the remaining lights will stay lit.
17. ANS:
conductors: metals, copper, silver; insulators: plastic, wood, rubber, glass
18. ANS:
It is determined by the density of the medium at the compressions.
19. ANS:
wavelength, frequency, and speed remain the same; amplitude increases
PROBLEM
20. ANS:
s = d/t = 10 km/40 min = 0.25 km/min
21. ANS:
d = s ´ y = 227 km/h ´ (2.00 h) = 454 km
22. ANS:
vf – vi/t = (96 m/s – 32 m/s)/ 8.0 s = 8.0 m/s2
23. ANS:
250 kg ´ m/s
p = mv = 10 kg ´ 25 m/s = 250 kg ´ m/s
24. ANS:
48 N
F = ma = 12 kg ´ 4 m/s2 = 48 kg ´ m/s2 = 48 N
25. ANS:
1/2 mv2 = 1/2 (18 + 62)(7)2 = 1,960 J
26. ANS:
(m)(9.8)(h) = (70)(9.8)(3) = 2,058 J
27. ANS:
(m)(9.8)(h) = (90)(9.8)(4) = 3,528 J
Short Answer:
1. Arrange each of the following in order from largest to smallest.
1. centimeter
2. kilometers
3. meters
4. micrometers
5. millimeters
2. Two cars start at the same point and drive in a straight line for 5 km. At the end of the drive their distances are the same but their displacements are different. Explain.
3. Two cars are traveling along the same road at the same speed but at different velocities. Explain.
4. A car is driving down a road. Is it possible for its position to be changing and its acceleration to be zero? Is it possible for its velocity to be changing and its acceleration to be zero?
5. A car has an acceleration of –5 m/s2. Describe the car’s motion.
6. If two equal forces act on an object in opposite directions, what is the net force? What is the acceleration?
7. Why is it necessary to wear a seat belt to hold you in place if you are riding in a car that stops suddenly?
8. Sally sits on a rock. Her weight is an action force. Describe its reaction force.
9. Explain how mass and weight are different from each other.
10. Why is your weight less on the Moon than on Earth, but your mass is the same?
11. Which body processes are fueled by chemical potential energy?
12. Is it possible for a ball to have both kinetic energy and potential energy at the same time? Explain.
13. Explain the changes in energy when a child slides down a sliding board.
14. How does the child's ride on the slide change if the slide is lubricated with water to make it slippery?
15. A dump truck, a sports car, and a bicycle are traveling at the same velocity. Compare their kinetic energies.
16. Describe how you could quickly determine whether a string of lights is wired in series or in parallel.
17. List two materials that are conductors and two materials that are insulators.
18. How is the amplitude of a compressional wave determined?
19. You shake the end of a rope to make a wave. You start shaking the rope a greater distance but at the same speed. How are the wavelength, frequency, amplitude, and speed affected?
Problems
20. A cross-country runner runs 10 km in 40 minutes. What is his average speed?
21. A high speed train travels with an average speed of 227 km/h. The train travels for 2 h. How far does the train travel?
22. Find the acceleration of a car that goes from 32 m/s to 96 m/s in 8.0 s.
23. A 10-kg wagon has a speed of 25 m/s. What is its momentum?
24. Calculate the force on an object that has a mass of 12 kg and an acceleration of 4 m/s2.
25. An 18-kg bicycle carrying a 62-kg girl is traveling at a speed of 7 m/s. What is the kinetic energy of the girl and bicycle?
26. A 70-kg boy is sitting 3 m from the ground in a tree. What is his gravitational potential energy?
27. A 90-kg ceiling light is suspended 4 m above the floor. What is its gravitational potential energy?
Phys Sci Question
Answer Section
SHORT ANSWER
1. ANS:
2, 3, 1, 5, 4
2. ANS:
The two cars drove in different directions.
3. ANS:
The two cars are traveling in different directions.
4. ANS:
Yes, it could have constant speed. No, a change in velocity is always an acceleration.
5. ANS:
The car is slowing down at the rate of 5 m/s every second.
6. ANS:
0, 0
7. ANS:
A seat belt helps to minimize injury from the inertia that keeps your body moving forward.
8. ANS:
The rock supplies an upward reaction force on Sally equal to her weight.
9. ANS:
Mass measures the amount of matter; weight measures the force of gravity on the matter.
10. ANS:
Your mass is the same because you didn't change the amount of matter, but the gravitational force decreased, decreasing your weight.
11. ANS:
heartbeat, digestion, warmth, movement
12. ANS:
a ball on a desk has potential energy; as it falls, it has both potential energy and kinetic energy
13. ANS:
At the top, he has 100% potential energy. As he slides, potential energy changes to kinetic energy and thermal energy because of friction. At the bottom of the slide his energy has transformed entirely into kinetic energy and thermal energy.
14. ANS:
Friction is decreased so more potential energy changes to kinetic energy without being lost to thermal energy. The child's ride is faster.
15. ANS:
Kinetic energy is based on mass and velocity. Given equal velocity, the dump truck has the most mass, so it has the most kinetic energy. The sports car would be next, and the bicycle last.
16. ANS:
Remove one bulb. If it's a series, all the lights will go out; if it's parallel, the remaining lights will stay lit.
17. ANS:
conductors: metals, copper, silver; insulators: plastic, wood, rubber, glass
18. ANS:
It is determined by the density of the medium at the compressions.
19. ANS:
wavelength, frequency, and speed remain the same; amplitude increases
PROBLEM
20. ANS:
s = d/t = 10 km/40 min = 0.25 km/min
21. ANS:
d = s ´ y = 227 km/h ´ (2.00 h) = 454 km
22. ANS:
vf – vi/t = (96 m/s – 32 m/s)/ 8.0 s = 8.0 m/s2
23. ANS:
250 kg ´ m/s
p = mv = 10 kg ´ 25 m/s = 250 kg ´ m/s
24. ANS:
48 N
F = ma = 12 kg ´ 4 m/s2 = 48 kg ´ m/s2 = 48 N
25. ANS:
1/2 mv2 = 1/2 (18 + 62)(7)2 = 1,960 J
26. ANS:
(m)(9.8)(h) = (70)(9.8)(3) = 2,058 J
27. ANS:
(m)(9.8)(h) = (90)(9.8)(4) = 3,528 J
# posted by Mr. Gibney @ 10:20 PM 
