Power Quiz

Student Name: Amira Lukens
Student Email: 1024885@wells-school.com

Site Title: Pearson Physics - Welcome to the eTest Companion Site
Location on Site: U3: Circular Motion, Work, and Energy > Chapter 6 > Section 6.4 eTest






70% Correct of 10 Scored items:
7 correct: 70%
3 incorrect: 30%



Submitted on December 12, 2012 at  8:24 PM (UTC/GMT)


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Question 1



Which of the following is not an expression of power?

Correct:



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Question 2



Use the following information to answer the next 2 questions.


A forklift raises a pallet full of goods weighing a total of 700 kg to a shelf 2.00 m high in 30.0 s.

What is the forklift's power output?


Correct: 458 J/s



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Question 3



If the forklift's motor must generate 550 W of power to lift the pallet, what is the motor's efficiency?

Incorrect: 46.0 %



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Question 4



Use the following information to answer the next 2 questions.


Quads are a common source of recreation in Alberta.







A particular quad with a mass of 300 kg is driving up a sand dune at a constant speed of 5.60 m/s. The force of resistance opposing its motion generated due to friction is 150 N. The dune's slope is 9.00° .



What is the forward force needed to maintain the quad's speed?



Correct: 610 N



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Question 5



Assume all the power output of the quad's engine goes into driving the quad up the slope. What is the power output of the quad's engine?

Incorrect: 2.58 kW



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Question 6



What is the relationship between the amount of work done and the power output of a machine?

Correct: Power is the rate of work being done.



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Question 7



Many trucks are equipped with winches. These winches are motor-powered spools that can be latched onto heavy objects, making it possible to pull them easily.






What is the relationship between the speed that an object is pulled by a winch and the power required by the motor to move the object?



Correct: As the speed of pulling increases, the power required increases.



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Question 8



Use the following information to answer the next 2 questions.


An empty elevator in a hotel (EL1) has a mass of 900 kg. It goes up to the 30th floor of a building, a total distance of 90.0 m, in 120 s. A freight elevator (EL2), with a mass of 2900 kg, goes up 4 floors in a building, a total distance of 12.0 m, taking 360 s.



What are the two elevators' power outputs?



Incorrect: EL1 is 675 W and EL2 is 6.40 x 104 W



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Question 9



If the freight elevator (EL2) goes up 10 floors (30.0 m) in 900 s, how does its power output change?

Correct: Its power output doesn't change.



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Question 10



A car engine is rated at 350 hp (1 hp = 746 W). How much work can it do in 30.0 min if its engine efficiency is 70%?

Correct: 3.29 x 108 J

Conservation of Energy Quiz

Student Name: Amira Lukens
Student Email: 1024885@wells-school.com

Site Title: Pearson Physics - Welcome to the eTest Companion Site
Location on Site: U3: Circular Motion, Work, and Energy > Chapter 6 > Section 6.3 eTest






80% Correct of 10 Scored items:
8 correct: 80%
2 incorrect: 20%



Submitted on December 12, 2012 at  8:16 PM (UTC/GMT)


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Question 1



Which of the following statements about an isolated system is false?

Correct: Objects in an isolated system can be subject to heat loss due to friction.



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Question 2



Which of the following correctly describes the law of conservation of energy?

Correct: In terms of mechanical energy, any gain in kinetic energy must be accompanied by an equal loss in potential energy.



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Question 3



The following graph illustrates the mechanical (EM), potential (EP), and kinetic (EK) energies for a block sliding down an inclined plane.






Which of the following best describes the changes in energy involved in this situation?



Incorrect: The sum of EP and EK must equal zero in this isolated system.



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Question 4



Hang-gliding is a popular sport that represents energy changes very well. As a hang-glider gains altitude, potential energy is gained. As the hang-glider gains velocity, kinetic energy is gained.






Assume that a hang-glider with a mass of 140 kg represents an isolated system. At one point the hang-glider has a speed of 10.0 m/s and is 200 m above the ground. Later, he/she is going 15.0 m/s. What is the gravitational potential energy when he/she is moving 15.0 m/s?



Correct: 2.66 x 105 J



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Question 5



Which of the following most closely resembles an isolated system?

Correct: A metronome (a pendulum-like gadget used to keep time) on a piano



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Question 6



A swing is a good example of a system in which energy is readily converted from potential to kinetic. If the girl in the photo is pushed up in the swing, she gains potential energy. As she gains speed when she swings, she gains kinetic energy.






Which of the following statements best describes this swing system?



Correct: The system is not isolated, due to loss of energy in the form of heat.



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Question 7



Use the following information to answer the next 2 questions.


A pendulum is a good example of a system in which energy is readily converted from potential to kinetic. As the pendulum bob gains altitude, it gains potential energy. As the pendulum bob gains speed, it gains kinetic energy.







At which point of the pendulum bob's motion does kinetic energy equal zero?



Correct: Point A



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Question 8



At which point of the pendulum bob's motion is kinetic energy at a maximum?

Correct: Point B



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Question 9



An ideal pendulum is suspended by a string that is 1.00 m long. The bob of the pendulum is pulled sideways and released. At the highest point of its swing the pendulum bob is 10.0 cm above the floor. At the lowest point the pendulum bob is 2.00 cm above the floor. The pendulum bob's mass is 20.0 g. What is the pendulum bob's maximum speed?

Correct: 1.25 m/s



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Question 10



Consider a frictionless trolley car coming down either one of two routes from a mountain. The first route is straight down the mountain's steep slope. The second route is a gentle winding path around and around the mountain to the same bottom point as the first route. Which statement about this situation is true?

Incorrect: The trolley will be going much faster down the steeper route and therefore will be at a higher speed at the bottom point.

Work Quiz

Student Name: Amira Lukens
Student Email: 1024885@wells-school.com

Site Title: Pearson Physics - Welcome to the eTest Companion Site
Location on Site: U3: Circular Motion, Work, and Energy > Chapter 6 > Section 6.2 eTest






30% Correct of 10 Scored items:
3 correct: 30%
7 incorrect: 70%



Submitted on December 12, 2012 at  8:13 PM (UTC/GMT)


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Question 1



Mechanics involves the study of forces in equilibrium, the study of motion, and the study of non-zero forces and the motion that results from them.


Which of the following is not an area of study under mechanics?



Correct: Workonics



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Question 2



By what must a change in kinetic energy always be accompanied?

Correct: A change in speed



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Question 3



Use the following information to answer the next 2 questions.


Many trucks are equipped with winches. These winches are motor-powered spools that can be latched onto heavy loads, making it possible to pull them easily. Suppose a winch is used to pull a car up a slippery incline at a constant speed of 2.0 km/h.







Consider this situation of winching a car. Which of the following is false?



Incorrect: The truck is exerting a zero net force on the car.



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Question 4



Suppose that the electrical current to the winch is increased, causing the car being pulled up a slippery slope to accelerate. Which of the following mathematical expressions does not represent the situation?

Incorrect:



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Question 5



A circus performer, with a mass of 140 kg, is flung from a catapult. At the peak of his trajectory his horizontal speed is 50 m/s and he is 300 m above the ground. With the ground as a reference point, what is the mechanical energy of the performer at the highest point in his trajectory?

Incorrect: 4.1 x 105 J



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Question 6



Choose the only answer that can complete the following statement. The work energy theorem states that ____________.

Incorrect: the work done on a system is always the change in its kinetic energy.



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Question 7



Which of the following statements concerning energy and energy change is true?

Incorrect: A change in kinetic energy can be accomplished without changing speed.



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Question 8



Imagine that you are taking a flight to Vancouver. You have a mass of 65 kg, begin at ground level, and are stationary. Later, at a particular point over the Rockies your body is 16 000 m above ground level and is travelling at 100 m/s.


Which of the following best describes the mechanical energy of your body?



Correct: Your body possesses much more gravitational potential energy than kinetic energy.



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Question 9



A lead shot fired from a shotgun has 200 J of kinetic energy. If it is travelling at 200 m/s, what is the mass of the lead shot?

Incorrect: 100 g



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Question 10



Choose the only answer that can complete the following statement. In order for work to be performed in a system, ___________.

Incorrect: a change in kinetic energy is required.

5.1 & 5.2 Pop Quiz

Student Name: Amira Lukens
Student Email: 1024885@wells-school.com

Site Title: Pearson Physics - Welcome to the eTest Companion Site
Location on Site: U3: Circular Motion, Work, and Energy > Chapter 6 > Section 6.1 eTest






50% Correct of 10 Scored items:
5 correct: 50%
5 incorrect: 50%



Submitted on November 15, 2012 at  1:44 AM (UTC/GMT)


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Question 1



Use the following information to answer the next 2 questions.


A helicopter flies you to a remote mountaintop. You pause to enjoy the view and then ski down to the bottom of the mountain.



Which of the following best describes the transfer of energy involved as you ski down the mountain?



Correct: Gravitational potential energy is converted to kinetic energy.



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Question 2



Which of the following best describes the change in energy involved in getting to the top of the mountain?

Incorrect: Work is done by the helicopter, resulting in an increase in kinetic energy.



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Question 3



A child is trying to push her toy box across the floor. She first pushes down on it at an angle and it does not move. She then pushes against it in the direction she wants it to go and it moves easily. Which choice describes this situation?

Correct: A force applied parallel to a displacement does the most work.



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Question 4



A man picks up an 8-kg cat and then holds it to his chest. Which statement about this situation is true?

Incorrect: You need to know how high he lifted the cat to calculate the force required to lift it.



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Question 5



An experiment involves placing a toy car at the top of a frictionless ramp in a backyard. Which statement below about this situation is false?

Incorrect: The change in potential energy would be the same if the experiment were repeated on the second-storey level of the house instead of the backyard.



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Question 6



A marble weighing 3.00 g rolls down a marble run from a height of 1.00 m to ground level. Which of the following represents the potential energy the marble has lost?

Incorrect: 29.4 J



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Question 7



The following graph represents the relationship between force and position for a mass suspended on a spring.






Which of the following best describes the relationship between force and position for this spring?



Correct: The slope of the line represents the spring constant.



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Question 8



Use the following information to answer the next 2 questions.


Old-style pinball machines are equipped with a spring for launching the ball into the machine.







Which of the following best describes when the spring is pulled back all the way and held, just before launching the ball?



Correct: The potential energy of the spring is at a maximum.



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Question 9



The pinball machine is equipped with a spring that has a relatively high spring constant. Which of the following statements regarding spring constants is false?





Incorrect: To calculate the force required to stretch a spring, a weight can be hung from the spring in a vertical position.



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Question 10



Two similarly constructed cars are set up to collide with a brick wall. One car is 2000 kg and will travel at 20 m/s. The other car is 4000 kg and will travel at 10 m/s. Which car will damage the wall the most, and why?

Correct: The 2000-kg car will do more damage to the wall because it has more kinetic energy.

Real World: Work, Force, Energy and Motion (Video Notes)

Work: the use of force to move an object a certain distance

When 'work' is done, the force must move in the same direction as the object's motion.

Work= Force x distance
 W=Fd
W=Newtons x meters
Newton x meters= Joules
Joules is the unit for work

Work can also be understood as a transfer of energy.

Energy is related to work.

2 types of energy: Potential (stored) energy and kinetic energy

A still object can still have energy within the system, that energy is potenital energy.

When a still object is suddenly put in motion the potential energy becomes kinetic energy, or the energy of motion.

Gravitational force has an affect on potential energy due to the fact that the distance of the object from the ground affects potential energy.

GPE=mgh
GPE= mass x gravity x height (meters)
Mass x gravity= Weight= Newtons

GPE= Weight(Newtons) x Meters
The unit for GPE is Joules.

Kinetic energy depends on mass and velocity.
KE= 1/2 mv^2

Sketch-up 3: Amira Marin

SKETCH-UP Rough Draft #2 AMIRA & MARIN

http://www.mediafire.com/?lvewi3prb1xi04l