Unit Test 222

Which formula can be used to find the centripetal acceleration of an orbiting object? ac = ac = ac = ac =

ac= v^2/r

What is the vertical acceleration of a paper airplane that is launched horizontally with an initial velocity of 2.3 m/s? -9.8 m/s2 0 m/s2 2.3 m/s2 9.8 m/s2

-9.8 m/s2

The gravitational force between two asteroids is 6.2 × 108 N. Asteroid Y has three times the mass of asteroid Z. If the distance between the asteroids is 2100 kilometers, what is the mass of asteroid Y? 3.7 × 1015 kg 1.1 × 1016 kg 1.4 × 1031 kg 4.1 × 1031 kg

1.1 × 1016 kg

Xavier throws a tennis ball to his friend Olaf at a 20° angle relative to the ground with an initial velocity of 18 m/s. The tennis ball travels 30 m until Olaf catches it. The time the tennis ball was in the air, rounded to the nearest hundredth, is

1.77 s

The table shows data for the planet Uranus. To the nearest whole number, how much would a 25.0 kg rock weigh on Uranus? 170 N 218 N 430 N 532 N

218 N

A bicycle tire has a radius of 0.23 m. The tire spins at a constant speed with a centripetal acceleration of 42 m/s2. What is the tangential speed of the tire? 3.1 m/s 6.5 m/s 9.7 m/s 14 m/s

3.1 m/s

Which best illustrates projectile motion?

D

The pitcher on a softball team starts a windup to throw a pitch, as shown. He wants to throw the pitch level with the ground and in the direction he is facing. At which point should he release the pitch? W X Y Z

W

A child on a spinning ride at a playground has a centripetal acceleration of 0.80 m/s2. The child completes a full circle every 4.2 s. How far from the center of the ride is the child? 0.068 m 0.085 m 0.27 m 0.36 m

0.36 m

A cyclist rides at a constant speed of 4.5 m/s around a curve. If the centripetal acceleration is 29 m/s2, what is the radius of the curve? 0.16 m 0.70 m 6.4 m 34 m

0.70 m

The diagram shows two vectors that point west and north. What is the magnitude of the resultant vector? 10 meters 50 meters 1200 meters 2500 meters

50 meters

An object is represented by the dot on the motion map. Which object is most likely represented by the dot? a car driving over the top of a hill a ball on a string that stopped at the top of a vertical loop a roller coaster car at the top of a vertical loop of track a bug on the top of a rolling hula hoop

a ball on a string that stopped at the top of a vertical loop

The acceleration due to gravity on Mercury is 3.7 m/s2, which is about six times the acceleration due to gravity on Pluto. Which statement accurately compares the mass and weight of an object on these two planets? An object weighs about one-sixth as much and has about one-sixth the mass on Pluto as on Mercury. An object weighs about one-sixth as much but has the same mass on Pluto as on Mercury. An object weighs the same but has about one-sixth the mass on Pluto as on Mercury. An object weighs the same and has the same mass on Pluto as on Mercury.

An object weighs about one-sixth as much but has the same mass on Pluto as on Mercury.

The diagram shows two balls released from a device at the same time. The ball on the left falls freely from rest, and the ball on the right is launched horizontally. Which best compares the vertical motion of the two balls? Both balls have constant velocity and are acted on by gravity. Both balls are acted on by gravity and are accelerating downward. Both balls are pulled downward and have zero acceleration. Both balls have zero acceleration and have constant velocity.

Both balls are acted on by gravity and are accelerating downward.

A boat travels in a straight path that is 25° west of north. Which describes the values of the west and north components of the boat's displacement? Both components are positive numbers. Both components are negative numbers. The west component is a negative number, and the north component is a positive number. The west component is a positive number, and the north component is a negative number.

The west component is a negative number, and the north component is a positive number.