Vocab
Practice Problems
Comprehension
100
A push or a pull
force
100
A 250 kg motorcycle is driven around a 12 meter radius of circular track at a constant speed of 11 m/s. What is the frictional force 
2,520 N
100
What is the direction of the force that keeps an object moving in a circle?
The force that is needed to keep an object moving in a circle is always directed toward the center of the circle along the radius.
200
A change in the direction of the velocity with respect to time
centripetal acceleration
200
a 5kg block of wood revolves around a 4m/s maintained by a centripetal force of 40N. At what radius does it revolve?
f=m v squared/r
200
What is the name of the force that keeps an object moving in a circle?
The force that keeps an object, moving in a circle, directed toward the center, is called the centripetal force.
300
a force directed toward the center to keep an object in a circular path.
Centripetal force
300
A 1000kg car rounds a turn of 30 meter radius at 9 m/s. What is it acceleration?
2.7m/s squared
300
Name the force that keeps an automobile moving in a circular path on a road.
For an automobile going around a circular path on the road, the force of friction between the tires and the road provides the centripetal force.
400
2 times pi times the radius of a circle
Circumference
400
A 1000kg car rounds a turn of 30 meter radius at 9 m/s.
What is the centripetal force?
400
Explain how the velocity of an object can change even if the speed is not changing.
Velocity is a vector quantity. All vectors have two components — size and direction. The size of the velocity vector is called the speed. When a moving object changes direction, the object’s velocity changes whether the speed changes or not.
500
the resistance that one surface or object encounters when moving over another
friction
500
A student is spinning a turntable with a wooden block resting on it. The block is located 10 cm from the center of the table, and the turntable is rotating 15 times every minute. What is the speed of the wooden block on the turntable?
15. 7 cm/s
500
What is the force that keeps Earth moving in a circle around the Sun?
The force that keeps Earth moving in a (roughly) circular path around the Sun is the
force of gravitational attraction between Earth and the Sun. This force on Earth is always directed toward the center of the solar system (the Sun).