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A boat moves 15.0 km across a lake in 45 min. What was the average speed of the boat in kilometers per hour? |
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If the Sun is a distance of 1.5 × 108 km from Earth, how long does it take sunlight to reach Earth if it moves at 3.0 × 108 m/s? |
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How many meters away is a cliff if an echo is heard 0.500 s after the original sound? Assume that sound traveled at 343 m/s on that day. |
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A car has an average speed of 80.0 km/h for one hour, then an average speed of 90.0 km/h for two hours during a three-hour trip. What was the average speed for the three-hour trip? |
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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 | |
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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8 | |
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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9 | |
How many hours are required for a radio signal from a space probe near the planet Pluto, 6.00 × 109 km away, to reach Earth? Assume that the radio signal travels at the speed of light, 3.00 × 108 m/s. |
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10 | |
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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11 | |
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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12 | |
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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13 | |
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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14 | |
Find the resulting acceleration from a 300 N force that acts on an object with a mass of 3,000 kg. |
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15 | |
What is the momentum of a 30.0 kg shell fired from a cannon with a velocity of 500 m/s? |
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16 | |
What is the momentum of a 39.2 N bowling ball with a velocity of 7.00 m/s? |
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17 | |
A 30.0 kg shell is fired from a 2,000 kg cannon with a velocity of 500 m/s. What is the resulting velocity of the cannon? |
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18 | |
An 80.0 kg man is standing on a frictionless ice surface when he throws a 4.00 kg book at 20.0 m/s. With what velocity does the man move across the ice? |
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19 | |
(a) What is the weight of a 5.00 kg backpack? (b) What is the acceleration of the backpack if a net force of 10.0 N is applied? |
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20 | |
What net force is required to accelerate a 20.0 kg object to 10.0 m/s2? |
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21 | |
What forward force must the ground apply to the foot of a 60.0 kg person to result in an acceleration of 1.00 m/s2? |
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22 | |
A 1,000.0 kg car accelerates uniformly to double its speed from 36.0 km/h in 5.00 s. What net force acted on this car? |
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23 | |
A net force of 3,000.0 N accelerates a car from rest to 36.0 km/h in 5.00 s. (a) What is the mass of the car? (b) What is the weight of the car? |
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24 | |
How much does a 60.0 kg person weigh? |
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25 | |
What tension must a 50.0 cm length of string support in order to whirl an attached 1,000.0 g stone in a circular path at 5.00 m/s? |
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26 | |
A 200.0 kg astronaut and equipment move with a velocity of 2.00 m/s toward an orbiting spacecraft. How long will the astronaut need to fire a 100.0 N rocket backpack to stop the motion relative to the spacecraft? |
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