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1 | |
In the absence of friction, air resistance, or other dissipative forces, the total kinetic energy remains constant. |
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| | A) | True |
| | B) | False |
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2 | |
The total energy of a system of bodies in isolation may be defined as the sum of the individual kinetic and potential energies. |
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| | A) | True |
| | B) | False |
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3 | |
All moving bodies possess kinetic energy. |
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| | A) | True |
| | B) | False |
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4 | |
The work of a resultant force on a body is equal to the change in kinetic energy. |
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| | A) | True |
| | B) | False |
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5 | |
As a body falls, its potential energy increases with its speed. |
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| | A) | True |
| | B) | False |
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6 | |
A 1-hp engine will do work at a faster rate than a 1-kW engine. |
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| | A) | True |
| | B) | False |
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7 | |
The kilowatthour is a unit of energy. |
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| | A) | True |
| | B) | False |
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8 | |
As an object falls freely from the top of a building, its total energy remains constant. |
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| | A) | True |
| | B) | False |
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9 | |
If we consider friction, the potential energy at the top of an inclined plane is less than it would be in the absence of friction. |
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| | A) | True |
| | B) | False |
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10 | |
According to convention, negative work means that the direction of the work is downward or to the left. |
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| | A) | True |
| | B) | False |
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11 | |
Which of the following is not necessary for work to be done? |
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| | A) | An applied force |
| | B) | A force component along the displacement |
| | C) | A displacement |
| | D) | A constant speed |
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12 | |
Which of the following is not a unit of work or energy? |
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| | A) | Newton-meter |
| | B) | Joule |
| | C) | Foot-pound per second |
| | D) | Kilowatthour |
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13 | |
The largest unit of power is the |
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| | A) | kilowatt |
| | B) | watt |
| | C) | foot-pound per second |
| | D) | horsepower |
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14 | |
A force of 20 N moves a 10-kg block through a distance of 400 cm. The work done by the 20-N force is |
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| | A) | 8000 J |
| | B) | 80,000 J |
| | C) | 80 J |
| | D) | 80 N * m |
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15 | |
A 10-kg block is lifted 20 m above the ground in a gravitational field. The work done by the field is |
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| | A) | negative |
| | B) | positive |
| | C) | equal to the final potential energy |
| | D) | a vector quantity |
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16 | |
In Question 15, the gravitational potential energy of the block after it has been lifted 20 m is |
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| | A) | 196 J |
| | B) | 1960 J |
| | C) | -1960 J |
| | D) | 200 J |
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17 | |
A 1-hp motor will lift a 200-lb block to what height in 2 s? |
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| | A) | 0.01 ft |
| | B) | 0.727 ft |
| | C) | 100 ft |
| | D) | 5.5 ft |
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18 | |
A block of mass m slides down an inclined plane of height h and slope distances. The kinetic energy at the bottom will be equal to |
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| | A) | mgh |
| | B) | ½mv² - Fs |
| | C) | mgh - Fs |
| | D) | mgh + Fs |
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19 | |
A 2-kg ball has a potential energy of 6400 J at a point A above the ground. What will its velocity be when it strikes the ground after being released from point A? |
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| | A) | 80 m/s |
| | B) | 28.3 m/s |
| | C) | 6400 m/s |
| | D) | 800 m/s |
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20 | |
A bullet whose initial kinetic energy is 400 J strikes a block where an 8000-N resistive force brings it to a stop. The depth of penetration into the wood is approximately |
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| | A) | unknown for lack of information |
| | B) | 0.2 m |
| | C) | 0.5 m |
| | D) | 0.05 m |
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21 | |
Three examples of potential energy are , , and . |
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22 | |
The work of a resultant external force on a body is equal to the change in of the body. |
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23 | |
The total mechanical energy of a body is the sum of its . This total is in the absence of friction. |
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24 | |
A force of 1 N acting through a distance of 1 m represents equal to 1 . |
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25 | |
is the rate at which work is done. |
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26 | |
The net work done by a number of forces acting on the same object is equal to the work of force. |
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27 | |
The kilowatthour is a unit of . |
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28 | |
When the resultant force on an object is opposite to the direction of displacement, the work is considered . |
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29 | |
Two things that are necessary in the performance of work are and . |
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30 | |
The product of force and velocity is a measure of . |
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