energy
One form of energy changes to one other form
single transformation
A light bulb converts electrical energy into both heat and light energy
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Light is one of the forms of electromagnetic energy.
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Mechanical energy is found by adding an object's potential energy and kinetic energy.
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Moving current has electrical energy.
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Nuclear reactions produce huge amounts of energy by transforming tiny amounts of matter.
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The temperature of a bottle containing water rises when it is shaken vigorously since shaking adds heat to the system
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To maintain your body temperature, your body converts chemical potential energy into thermal energy.
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All of the following statements are true of hydroelectric power EXCEPT:
Hydroelectric power stations can only produce enough energy for a small town as they do not produce large quantities of energy.
What is the kinetic energy of a 0.135 kg baseball thrown at 40.0 m/s?
108
How much elastic potential energy is stored in a bungee cord with a spring constant of 10.0 N/m when the cord is stretched 2.00 m?
20
The mass of ball B is 1 kilogram and its speed is 1 m/sec. The mass and the speed of ball A is three times the mass and the speed of ball B. What is the ratio of the kinetic energy of ball A to ball B? Hint: Divide the kinetic energy equation for ball A by the kinetic energy equation of ball B.
27
A 3.00 kg toy falls from a height of 1.00 m. What will the kinetic energy of the toy be just before the toy hits the ground? (Assume no air resistance and that g = 9.81 m/s.)
29.4 J
If the displacement of a horizontal mass-spring system was doubled, the elastic potential energy in the system would change by a factor of
4
50 g of ice at 0°C is dropped in a beaker containing 100 g of water at 0°C. What will be the contents of the beaker after 5 hours? Assume that the room temperature is 0°C.
50 g of ice and 100 g of water
5000 J of heat is supplied in one minute to 0.06 kg of a liquid at its boiling point of 85°C to convert it completely to vapor. Which of the following expressions gives the heat of vaporization of the liquid?
5000/0.06 J/kg
A 20.0 kg block of ice is sitting in a cooler. The temperature of the ice is 0.0ºC when it is put into the cooler. As it melts, how much heat does the block of ice absorb? (Remember Hf of water is 3.34 X 105 J/kg)
6.68 X 106 J
Visible light is an example of
electromagnetic energy.
An __________ force is a force that changes the mechanical energy of an object, for example, ________.
external, friction
When work is done on an object by an________________force, there will be a change in the total mechanical energy of the object. If _______________ forces do work, total mechanical energy will be conserved.
external, internal
If the horizontal line represents the reference point, the pendulum has
only kinetic
Which of the following energy forms is associated with an object due to its position?
potential energy
A soft drink company is marketing a new energy drink with the claim that "100 mL yields 1.7 kJ." The can contains 375 mL. Stephanie drinks the entire can and then wants to test the claim made by the company by climbing stairs. How high would Stephanie have to climb to test the claim if she has a mass of 65.0 kg?
1.0 x 101 m
Which equation expresses the conservation of mechanical energy in a system where the only forms of mechanical energy are kinetic energy and gravitational potential energy?
1/2mvi2 + mghi = 1/2mvf2 + mghf
Which situation illustrates conservation of mechanical energy?
A pendulum swinging back and forth.
How would you calculate an object's mechanical energy?
Add its kinetic and potential energies
What is true about mechanical energy?
An object with mechanical energy can exert an applied force on another object
A roller coaster starts from rest at point A and continues to point B on a frictionless track. What best describes the changes in kinetic and potential energy as the car travels from point A to point B?
Kinetic energy increases, and potential energy decreases.
Why doesn't the principle of mechanical energy conservation hold in situations when frictional forces are present?
Kinetic energy is not completely converted to a form of potential energy.
Which equation expresses the conservation of mechanical energy using only the basic term for mechanical energy?
MEi = MEf
What are the units for a spring constant?
N/m
How do pressure cookers affect phase change in water?
Pressure cookers increase the boiling point of water
Why is mass multiplied by the speed of light squared in Einstein's famous equation?
The energy created is moving at the speed of light
Why isn't there a change in temperature during a phase change?
The energy would be used by the increasing motion of molecules
Which best describes the conservation of energy as a pendulum swings in the path shown below?
The potential energy at point A is equal to the kinetic energy at point B.
Which of the following is a true statement about the conservation of energy?
Total energy is always conserved.
What type of conversion is taking place when natural gas is used to heat water?
chemical energy into thermal energy
What forces act on the cars of a roller coaster when they enters loops and turns after reaching the initial summit?
What forces act on the cars of a roller coaster when they enters loops and turns after reaching the initial summit?
Gravitational potential energy is always measured in relation to
a zero level.
Which of the following forms of energy is NOT mechanical?
all of the above are not mechanical
Heat is added to an open container of a liquid. The liquid is brought to its boiling point and half the liquid boils away. Which of the following graphs shows how the temperature changes with time in this period?
b
A roller coaster car starts with an initial speed of 0.375 m/s from the top of a section of a track that is sloping down at 26.2° to the horizontal. After traveling 80.3 m, it reaches the end of that section of the track and continues up the next section of the track that slopes up at 22.4° to the horizontal. If this section of the track has a length of 73.2 m, the car will not reach the top of the section.
f
According to the First Law of Thermodynamics, the change in thermal energy of an object is equal to the heat added to the object divided by the work done by the object.
f
An electric motor converts electrical energy to potential energy.
f
An ice cube melts when its mechanical energy increases.
f
Mechanical energy is associated only with the motion of an object.
f
Temperature is another name for thermal energy.
f
The temperature of a system must increase when heat energy is added.
f
Which of the following is a form of mechanical energy?
gravitational potential energy
The amount of energy that is needed to melt 1 kg of a substance
heat of fusion
Calculated by the equation KE = 1/2mv2
kinetic energy
Which of the following energy forms is associated with an object in motion?
kinetic energy
What type of energy is present in a barbell being lifted or a shot-put being thrown?
mechanical energy
Which of the following are examples of conservable quantities?
mechanical energy and mass
When you rub your hands together on a cold day, you use friction to convert
mechanical energy into thermal energy.
Energy stored in the nucleus of an atom is called
nuclear energy.