| A | B |
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| Missy's favorite ride at the Topsfield Fair is the rotor, which has a radius of 4.0 m. The ride takes 2.0 s to make one full revolution. What is Missy's speed on the rotor? What is Missy's centripetal acceleration on the rotor? | 12.57 m/s; 39.48 m/s^2 |
| Luigi twirls a round piece of pizza dough overhead with a frequency of 60 revolutions per minute. Find the speed of a stray piece of pepperoni stuck on the dough 10 cm from the pizza's center. | 0.628 m/s |
| To test their stamina, astronauts are subjected to many rigorous physical tests before they fly in space. One such test involves spinning the astronauts in a device called a centrifuge that subjects them to accelerations far greater than gravity. With what speed would an astronaut have to spin in order to experience an acceleration of 3 g's at a radius of 10 m? | 17.15 m/s |
| Roxanne is making a strawberry milkshake in her blender. A tiny, 0.0050-kg strawberry is rapidly spun around the inside of the container with a speed of 14.0 m/s, held by a centripetal force of 10 N. What is the radius of the blender at this location? | 0.098 m |
| The gravitational force of attraction between Earth and the Sun is 1.6 x 10^23 N. What would this force have been if Earth had been twice as massive? | 3.2 x 10^23 N |
| The gravitational force of attraction between Earth and the Sun is 1.6 x 10^23 N. What would this force have been if Earth had formed twice as far away from the Sun? | 4.0 x 10^22 N |
| Mr. Gewanter, whose mass is 60.0 kg, is doing a physics demonstration in the front of the classroom. How much gravitational force does he exert on 55.0-kg Martha in the front row, 1.50 m away? How does this compare to what he exerts on 65.0-kg Lester 4.00 m away in the back row? | 9.78 x 10^-8 N; the force on Martha is greater than that on Lester (1.63 x 10^-8 N) |
| What distance separates a 100-kg football player and a 40-kg ballerina if the force between them is 2.95 x 10^-9 N? | 9.51 m |
| In "The Little Prince," the Prince vists a small asteroid called B612. If asteroid B612 has a radius of only 20.0 m and a mass of 1.00 x 10^4 kg, what is the acceleration due to gravity on asteroid B612? | 1.67 x 10^-9 m/s^2 |
| Two satellites of equal mass are put into orbit 30 m apart. If the gravitational force between them is 2.0 x 10^-7 N, find the mass of each satellite. | 1643 kg |
| What is the centripetal acceleration of a point on the perimeter of a bicycle wheel of diameter 50 cm when the bike is moving at 10 m/s? | 400 m/s^2 |
| A car traveling at 30 m/s rounds a 90-m-radius horizontal curve with the tires on the verge of slipping. What is the coefficient of friction between the tires and the road? How fast can the very same car round a second curve of radius 350 m? (Assume the same coefficient of friction between both road surfaces.) | 1.02; 59.16 m/s |
| A race car travels around a circular track of radius 50 m at a speed of 40 m/s. If a second race car travels around the same track at a speed of 46 m/s, how does the centripetal acceleration of the second car compare to the centripetal acceleration of the first car? | 1.3225 times greater |
| A hypothetical planet has a mass and radius 3 times that of Earth. If an object weighs 20 N on the surface of Earth, how much would it weigh on the surface of this planet? | 6.67 N |
| A 1.5-kg rock is tied to a string 40 cm long and spun around in a horizontal circle. If the string will break when the tension in it exceeds 250 N, what is the greatest speed the rock can have without breaking the string? | 8.16 m/s |
