Exam Review 101 – “If you can do this on your own own own, you’ll do very very very well for your exam”
Part I: Motion and Forces, Work and Energy
1.
Review position time graphs, velocity time graphs and acceleration time graphs.
2.
Draw the related velocity time graph for the motion of this car.
One day, Mr. Sciarretta is traveling from home to ND. He is travelling West on Bovaird at a constant speed of 20 m/s (Mr. Sciarretta
follows all traffic laws, including the speed limit) for 1 minute. As he approaches an intersection, he notices that the light has turned red
and hence he decelerates and comes to a stop in 15 seconds. Suddenly, Mr. Sciarretta notices that he forgot his Physics exam at home (so
he makes a U-Turn) and accelerates uniformly to a speed of 25 m/s in 10 seconds. He then travels at this speed for the next 2 minutes
until he arrives home.
a)
b)
c)
d)
e)
Find the acceleration of the car during each section of motion.
Find the total distance traveled by the car.
Find the displacement during the trip.
Draw the related position time graph (assuming that the initial position of the car was at 0 m)
Draw the related acceleration time graph.
3.
How long does it take for a 50 g. ball to roll 8.0 m[F] with a constant velocity of 2.0 m/s [F]
4.
a)
b)
A car (F1 Williams driven by Juan Montoya) is in the pits and is moving at 7 m/s [W] accelerates uniformly such that in 12 s the
vehicle has undergone a displacement of 125 m[W].
What is the car’s final velocity?
What is the car’s acceleration?
5.
a)
b)
A horse makes two complete laps around an 800 m track in 4 mins. Find
the average speed of the horse.
The average velocity of the horse.
6.
A train (carrying super spy Agent 001, with the secret formula on how Cadbury gets its Caramel in its milk chocolate bar) slows
down from 25 m/s [E] to 18 m/s [E] in 4 s. Find the acceleration of the train.
7.
A ball is rolled up a ramp with an initial velocity of 5 m/s [U]. 4 seconds later, it is moving down the ramp with a velocity of 3 m/s
[D]. What is the acceleration of the ball and at when was the ball stationary?
8.
What displacement is covered by a cat (who is running after a mouse) if its initial velocity was 6 m/s [N] and uniformly slows down
at a rate of 0.5 m/s2 [N] to a final velocity of 1.2m/s[N].
9.
An old shoe is dropped out of a window. The window is 14.2 m above the cat (the person who dropped the shoe is a lab researcher
who was conducting an important experiment on the mouse that was being chased in question 8 and hence wants to defend her
investment). With what velocity is the unsuspecting kitty struck (oh yes, the mouse escapes to live another day, the researcher wins
the Nobel Science Prize for her discovery with that mouse…….and the kitty was not injured….it’s true)?
10. A graduation cap (the Physics students have just graduated from ND, and are extremely happy and will always remember those
famous words….oh yes……its true……and Plug it in) is tossed up into the air. The maximum height reached by the cap is 3 m.
With what velocity was the cap thrown?
11. What is the acceleration of a 5.7 kg sled which has the following forces acting on it: 10.2 N[F], 55.9 N [D], 3.7 N [B], 8.1 N[B], 6.6
N [F] and 55.9 N [U].
12. On the surface of the earth, a tennis player has a weight of 539 N. What is the tennis player’s mass?
13. A toy rocket has opened up its parachute and is returning to earth. It has a mass of 1.2 kg and experiences a buoyancy force of 10 N.
If the rocket is 24 m above the earth and has an initial velocity of 0m/s, how long will it take it to hit the surface of the earth?
14. A 10 kg toy rocket accelerates upward and has a force of air resistance of 5 N acting on it. The engine generates 133 N of force.
a) What is the height the rocket will reach after 3 seconds (assume the initial velocity is 0m/s)?
b) If the rocket experienced a greater amount of air resistance, how would this affect the height it reached after 3 s?
15. A Dodge Viper accelerates from 0 m/s to 20 m/s in a time of 4 seconds. The Viper has a mass of 1000 kg. The applied force
generated by the Viper is 6000N. Find the force due to air resistance acting on the Viper.
16. Calculate the action-reaction pair of forces.
17. A 25 kg crate is being pushed with a force of 10 N over a distance of 10 m. How much work has the person done?
18. How much power is produced in lifting a 12 kg. knapsack (boy those textbooks are heavy) onto a desk that is 2.2 m high in 1.85
seconds.
19. What is the potential energy of a 2 kg bunch of bananas hanging from a tree 3.6 m high?
20. Calculate the speed of a 16 kg curling stone if it has a kinetic energy of 110 J?
21. A large 1.4 kg. water balloon is thrown out of a window with a speed of 1 m/s. The window is 10 m above the ground.
a) What is the total energy of the water balloon?
b) With what speed does the balloon strike the ground?
22. 10000 J of energy are added to water, which has a specific heat capacity of 4200 J/kgC. The water started out at 10 degrees Celsius.
Find the final temperature of the water if the mass of the water is 150 g.
23. Find the energy added to water if its temperature rises from 10 degrees C to 50 degrees C in a time of 10 seconds, and its mass is
5000 g.
Part II: Sound and Waves
24.
a)
b)
c)
d)
e)
A sound wave produced by a tuning fork travels with a speed of 342 m/s. It has a frequency of 1600 Hz.
What is the wavelength of the sound wave?
What is the period of the wave?
If the temperature increases, how does this effect the frequency of the wave?
If the temperature increases, how does this effect the wavelength?
Tape has now been added to the tuning fork, causing the frequency to decrease. How does this effect the speed of sound?….. the
wavelengh?
25. A pendulum has an amplitude of 4 cm and completes 24 cycles in 20 s.
a) What is the frequency of the pendulum?
b) What is the period of the pendulum?
26. A concert is being played outdoors at the Molson Ampitheatre. The lead singer of U2 asks the fans, “If you are in section 5, row
150, and are exactly 200 meters away from the speaker, how long does it take for you to hear the sound coming from the speaker if
the air temperature is 24 degrees Celsius?”
27. A steamer approaches a steep precipice several kilometers away and sounds a short blast on its horn. The echo is heard 20s later.
Twenty minutes later, another blast produces an echo in 6 seconds. Find the speed of the ship if the speed of sound is 345.2 m/s.
28. What is a beat? What are they used for? When do they occur?
29. A tuning fork is held over a tube that is closed at one end. The first resonant length is found to be 75 cm. Find the frequency of the
fork if the speed of sound is 340 m/s.
30. An air column open at both ends has a 3rd resonant length of 45 cm. What is the 4th resonant length?
31. An air column closed at one end has a 4th resonant frequency of 1000 Hz. If the speed of sound is 335 m/s, calculate the length of
the air column.
32.
a)
b)
c)
d)
Calculate the shortest possible resonant length (speed of sound is 344 m/s) when a 688 Hz tuning fork is held over the opening of:
an air column open at both ends
an air column closed at one end
What happens to the resonant length as the temperature increases?
What happens to the resonant length as the frequency of the tuning fork increases?
33.
a)
b)
c)
A string has a first harmonic frequency of 300 Hz (speed of sound is 340 m/s). Find
the length of the string
the frequency of the second harmonic
the wavelength of the second harmonic frequency
34. A standing wave is formed which travels at a speed of 1.2 m/s. There are a total of 1.5 waves. Find the frequency if the length of
the wave is 3 meters.
Part III: Error Analysis
35. During a physics experiment, a ball is dropped from a height of 2 m above the ground. Each student in the class has his/her own
stopwatch and records the time it takes for the ball to drop that height. The experiment is repeated 10 times and the results are
averaged. An average time of 0.70 seconds is calculated from the experimental results.
a) Calculate the acceleration due to gravity based on the experimental result.
b) Using an error of +/-0.1 seconds, calculate the range of time values that can occur in this experiment.
c) Using your answer in part b), calculate the range of possible values for the acceleration due to gravity.
d) Is your answer in c) within the accepted value for the acceleration due to gravity?
e) What parameters of the experiment can you adjust in order to improve your results?
Solutions:
2. a) A – 0 m/s2
B - -1.33 m/s2 [W] C – 2.5 m/s2 [E]
b) 1200 m + 150 m + 125 m + 3000 m
a) 1200 m [W] + 150 m [W] + 125 m [E] + 3000 m [E]
3. 4 seconds
4. a) 13.83 m/s[W]
b) 0.57 m/s2 [W]
5. a) 6m/s
b) 0 m/s
6. –1.75 m/s2 [E]
7. 7. 2 m/s2 [D], 2.5 seconds
8. 34.6 m [N]
9. 9. 16.7 m/s [D]
10. 7.67 m/s
11. 0.88 m/s2 [F]
12. 55 kg
13. 5.7 seconds
14. 13.5 m
15. –1000 N
16. 20.86 N
17. 100 J
18. 139.8 W
19. 70.6 J
20. 3.71m/s
21. 137.95 J
b) 14 m/s
22. 26 degrees Celsius
23. 840 000 J
24. a) 0.21 m
b) 0.000625 s
c) no effect
d) wavelength inc. e) no effect, wavelength inc.
25. a) 1.2 Hz
b) 0.83 s
26. 0.58 seconds
27. 2 m/s
28.
29. 113.3 Hz
30. 60 cm
31. 0.586 m
32. a) 0.25 m
b) 0.125 m
c) inc.
d) dec.
33. a) 0.567 m
b) 600 Hz
c) 0.567 m
34. 0.6 Hz
35. a) 8.16 m/s2
b) 0.6 s, 0.8 s
c) 11.11 m/s2, 6.25 m/s2