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1 | |
When a rock is made to move in a circular path at the end of a string, an outward force is exerted on the rock. |
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| | A) | True |
| | B) | False |
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2 | |
If the string breaks in Question 1, centripetal acceleration will cause the rock to move inward. |
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| | A) | True |
| | B) | False |
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3 | |
Centripetal and centrifugal forces have the same magnitudes but are opposite in directions; they don’t cancel because they act on different objects. |
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| | A) | True |
| | B) | False |
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4 | |
When a car moves in a horizontal circle on a level road, the centripetal force is exerted by the tires. |
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| | A) | True |
| | B) | False |
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5 | |
The maximum speed with which a car can negotiate a curve does not depend on the weight of the car. |
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| | A) | True |
| | B) | False |
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6 | |
The period of revolution may be thought of as the number of complete revolutions per second. |
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| | A) | True |
| | B) | False |
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7 | |
Just as a resultant force is needed to change the speed of a body, a resultant force is necessary to change its direction. |
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| | A) | True |
| | B) | False |
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8 | |
Uniform circular motion is motion in which the linear speed changes at a constant rate. |
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| | A) | True |
| | B) | False |
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9 | |
The formula for computing the banking angle also applies for the angle that the cord makes with the vertical for a conical pendulum. |
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| | A) | True |
| | B) | False |
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10 | |
If two masses are separated by twice the distance, they will experience one-half the gravitational attraction. |
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| | A) | True |
| | B) | False |
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11 | |
A ball is tied to a string and swung in a horizontal circle. When the string breaks, the ball will follow a path that is |
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| | A) | toward the center |
| | B) | away from the center |
| | C) | at a tangent to its circular path |
| | D) | none of these |
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12 | |
The force exerted on the ball in Question 11 is a |
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| | A) | centrifugal force |
| | B) | centripetal force |
| | C) | gravitational force |
| | D) | fictitious force |
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13 | |
A body traveling in a circular path at constant speed |
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| | A) | has an outward acceleration |
| | B) | has inward acceleration |
| | C) | has constant velocity |
| | D) | is not accelerated |
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14 | |
An object makes one complete revolution in 0.5 s. Its frequency is |
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| | A) | 2 s |
| | B) | 5 rev/s |
| | C) | 2 rev/s |
| | D) | 0.5 rev/s |
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15 | |
An object swings at the end of a string in uniform circular motion. Which of the following changes would not cause an increased centripetal force? |
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| | A) | A longer string |
| | B) | A shorter string |
| | C) | A greater linear speed |
| | D) | A larger mass |
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16 | |
The linear speed of an object swinging in a circular path of radius 2 m with a frequency of 5 rev/s is |
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| | A) | 2 Π m/s |
| | B) | 20 Π m/s |
| | C) | 4 Π m/s |
| | D) | 10 Π m/s |
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17 | |
The centripetal acceleration of a 2-kg mass swinging in a 0.4-m radius with a linear speed of 4 m/s is |
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| | A) | 4 m/s² |
| | B) | 40 m/s² |
| | C) | 10 m/s² |
| | D) | 20 m/s² |
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18 | |
An 8-kg ball is swung in a horizontal circle by a cord of length 2 m. If the period is 0.5 s, the tension in the cord is approximately |
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| | A) | 264 N |
| | B) | 202 N |
| | C) | 1200 N |
| | D) | 2527 N |
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19 | |
The banking angle for a curve of radius 400 ft for a speed of 60 mi/h should be approximately |
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| | A) | 31° |
| | B) | 16° |
| | C) | 26° |
| | D) | 37° |
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20 | |
The gravitational constant is 6.67 x 10-11 N * m²/kg². What is the gravitational force between two 4-kg balls separated by 0.2 m? |
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| | A) | 5.34 x 10-7 N |
| | B) | 2.67 x 1-8 N |
| | C) | 1.33 x 10-8 N |
| | D) | 6.67 x 10-8 N |
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21 | |
Uniform circular motion is motion in which there is no change in but only a change in . |
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22 | |
The is the number of revolutions per unit of time, whereas the is the time for one revolution. |
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23 | |
For a body moving in a horizontal circle, doubling the linear speed has the effect of increasing the centripetal acceleration by a factor of . |
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24 | |
The gravitational force between two particles is directly proportional to the product of their and inversely proportional to the of the between them. |
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25 | |
The force required to keep mass moving in a circular path at constant speed v is called the force and has a magnitude equal to , where R is the radius of the circle. |
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26 | |
The proper banking angle θ to eliminate the necessity for a frictional force is given by the relation , where v is the velocity, R is the radius of the curve, and g is the acceleration due to gravity. |
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27 | |
Whenever the centripetal force acts on an object, there is an equal and opposite force exerted by the object. |
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28 | |
When a curve is not banked, the centripetal force is provided by . |
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29 | |
The speed is the minimum speed needed to maintain circular motion in a vertical plane. |
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30 | |
The correct set of USCS units for the gravitational constant is . |
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