Note: Neglect all frictional forces in all exercises.
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1 | | A boat moves 15.0 km across a lake in 45 min. (a) What was the average speed in meters per second? (b) What was the average speed in kilometers per hour? |
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2 | | If the Sun is a distance of 1.5 x 108 km from Earth, how long does it take sunlight to reach earth if it moves at 3.0 x 108 m/s? |
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3 | | How many meters away is a cliff if an echo is heard one-half second after you yell "hello"? Assume that sound traveled at 343 m/s on that day. |
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4 | | A car has an average speed of 80.0 km/hr for one hour, then an average speed of 90.0 km/hr for two hours during a three-hour trip. (a) How far did the car travel during the trip? (b) What was the average speed for the trip? |
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5 | | What is the acceleration of a car that moves from a speed of 5.0 m/s to a speed of 15 m/s during a time of 6.0 s? |
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6 | | How much time is needed for a car to accelerate from 8.0 m/s to a speed of 22 m/s if the acceleration is 3.0 m/s2? |
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7 | | What was the initial speed of a car that required 13.7 m to stop in 4.00 s? |
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8 | | What is the average speed of a car that travels 270.0 miles in 4.50 hours? |
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9 | | A ferryboat requires 45.0 min to travel 15.0 km across a bay. (a) What was the average speed in m/s? (b) At this speed, how much time would be required for the boat to take a 420 km trip up the river? |
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10 | | A car with an average speed of 60.0 mi/hr (a) will require how much time to cover 300.0 miles? (b) will travel how far in 8.0 hours? |
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11 | | A rocket moves through outer space at 11,000 m/s. At this rate, how much time would be required to travel the distance from Earth to the Moon, which is 380,000 km? |
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12 | | Sound travels at 1,140 ft/s in the warm air surrounding a thunderstorm. How far away was the place of discharge if thunder is heard 4.63 s after a lightning flash? |
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13 | | How many hours are required for a radio signal from a space probe near the planet Pluto, 6.00 x 109 km away, to reach Earth? Assume that the radio signal travels at the speed of light, 3.00 x 108 m/s. |
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14 | | A rifle is fired straight up, and the bullet leaves the rifle with an initial velocity magnitude of 724 m/s. After 5.00 s the velocity is 675 m/s. At what rate is the bullet decelerated? |
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15 | | An airplane is accelerated uniformly from rest to 95.0 m/s in 6.33 s. What is the acceleration of the plane? |
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16 | | A racing car accelerates from 40.0 m/s to 80.0 m/s in 10.0 s. What is the acceleration? |
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17 | | What is the velocity of a car that accelerates from rest at 6.0 m/s2 for 5.0 s? |
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18 | | A car with an initial velocity of 30.0 m/s is able to come to a stop over a distance of 100.0 m when the brakes are applied. (a) How much time was required for the stopping process? (b) How many g's did the driver experience? |
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19 | | A rock thrown straight up climbs for 2.50 s, then falls to the ground. Neglecting air resistance, with what velocity did the rock strike the ground? |
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20 | | An object is observed to fall from a bridge, striking the water below 2.50 s later. (a) With what velocity did it strike the water? (b) What was its average velocity during the fall? (c) How high is the bridge? |
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21 | | A ball dropped from a window strikes the ground 2.00 seconds later. How high is the window above the ground? |
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22 | | What is the resulting velocity if a car moving at 10.0 m/s accelerates at 4.00 m/s2 for 10.0 s? |
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23 | | If a rock in free fall is moving at 96.0 ft/s, how long has it been falling? |
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