Ucm

A motorcyclist moves at a constant speed down one hill and up another hill along the smooth curved surface. When the motorcyclist reaches the lowest point of the curve its velocity and acceleration directions are

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Tags

NGSS.HS-PS2-1

A car goes around a curve of radius r at a constant speed v. Then it goes around the same curve at half of the original speed. What is the acceleration of the car as it goes around the curve for the second time, compared to the first time?

• twice as big

• four times as big

• half as big

• one-fourth as big

Tags

NGSS.HS-PS2-1

A car goes around a curve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal acceleration of the car as it goes around the second curve, compared to the first?

• four times as big

• twice as big

• one-half as big

• same value as the first

Tags

NGSS.HS-PS2-1

A rope attaches a tire to an overhanging tree limb. A girl swinging on the tire has a centripetal acceleration of 3.0 m/s^2. If the length of the rope is 2.1 m, what is the girl’s tangential speed?

• 3.5 m/s
• 2.5 m/s
• 8.5 m/s
• 12.5 m/s

As a young boy swings a yo-yo parallel to the ground and above his head, the yo-yo has a centripetal acceleration of 250 m/s^2. If the yo-yo’s string is 0.50 m long,what is the yo-yo’s tangential speed?

• 11 m/s
• 15 m/s
• 111111111111111111111112 m/s
• 22 m/s

A dog sits 1.5 m from the center of a merry-go-round. The merry-go-round is set in motion, and the dog’s tangential speed is 1.5 m/s. What is the magnitude of the dog’s centripetal acceleration?

• 3.9 m/s^2
• 2.8 m/s^2
• 1.5 m/s^2
• 11.5 m/s^2

A racecar moving along a circular track has a centripetal acceleration of 15.4 m/s².If the car has a tangential speed of 30.0 m/s, what is the distance between the car and the center of the track?

• 33.7 m
• 88.6 m
• 44.2 m
• 58.4 m

A wheel has a frequency of 10 Hz and a speed of

30 m/s. What is the radius of this wheel? (take π = 3)

• 0.7 m

• 0.5 m

• 0.3 m

• 0.4 m

Tags

NGSS.HS-PS4-1

An object makes fourth revolution in 2 second. What is the frequency of the object?

• 4 Hz

• 1/2 Hz

• 1/4 Hz

• 2 Hz

Tags

NGSS.HS-PS4-1

A bicycle has period 0.3s . What is the

speed of its tires if their radius is 30 cm?

• 6 m/s

• 3 m/s

• 60 m/s

• 30 m/s