Relative Velocity
When a problem has multiple frames of reference, ____ is used to determine relative velocity.
Vector addition
In uniform circular motion, there is a:
a. constant velocity
b. constant angular velocity
c. zero acceleration
d. non-zero tangential acceleration
b. constant angular velocity
Andrew turns on his 4 kg electric train and it goes around its circular track in 7 seconds. If the track has a radius of 2 meters, determine the centripetal acceleration.
1.61 m/s^2
The apparent force that seems to pull on a moving object away from the center, but doesn't exert a physical outward push on it.
A 2.0 kg rock is moving in a 0.5 m horizontal circle every 0.25 s. Which of the following does the rock experience?
a. no net force
b. a centripetal acceleration
c. only the acceleration of gravity
d. motion due only to its inertia
b. a centripetal acceleration
You’re on a train that is travelling with a velocity of 45m/s North. You get out of your seat and walk towards the back of the train with a speed of 1.5m/s. What is your relative velocity to the ground?
43.5 m/s north
2.4 m/s
A runner moving at a speed of 9.10 m/s rounds a bend with a radius of 22.0 m. What is the centripetal acceleration of the runner? Round your answer to the nearest tenth.
3.8 m/s^2
The ________ force supplies the centripetal force requirement for the car to move in a horizontal circle. Without it, the car would turn its wheels but would not move in a circle (as is the case on an icy surface).
Friction Force
A ball was swung at constant speed in a horizontal circle on the top of a level lab table. Which of the following was the direction of the acceleration on the ball?
a. The acceleration was inward along the radius of the circle.
b. The acceleration was outward along the radius of the circle.
c. The acceleration was tangent to the circle in the direction of the ball's motion.
d. The acceleration was perpendicular to both the ball's motion and the tabletop.
a. The acceleration was inward along the radius of the circle.
Two cyclists, Alice and Bob, are riding on a straight path in the same direction. Alice is cycling at 15 m/s, while Bob is cycling at 10 m/s. Find Alice’s relative velocity as seen by Bob.
5 m/s
Pearl the Joker whirls a 8.00 kg hammer tied to the end of a 1.3 m chain in a horizontal circle. The hammer makes one revolution in 2.0 s at a constant speed. What is the speed of the hammer around John?
4.084 m/s
A toy car is following a circular path with a constant speed of v=3 m/s . If the radius of the circular path is 1 m, find The centripetal acceleration of the car
9 m/s^2
A 250 kg motorcycle goes around a 20.0 m radius turn at 19.0 m/s. What is the centripetal force on the motorcycle?
4512.5 N
What appears to have the fastest relative velocity?
a. the bus seen from the sidewalk by a standing pedestrian
b. a bus heading the opposite direction as your car
c. a bus heading the same direction as your car
b. a bus heading the opposite direction as your car
A boat moves north at a speed of 2.7 m/s across a river that flows west at a rate of 1.2 m/s. What is the boat's velocity relative to the river bank?
2.95 or 3 m/s
The velocity vector for an object in uniform circular motion is ____.
tangential to the circle
A car moves with a constant speed of 17 m/s on a circular track of 200 m radius. Calculate the acceleration of the vehicle.
1.45 m/s^2
247.65 N
Akhila is riding on the merry-go-round and is moving with a speed of 2.00 m/s when she is 2.08 m from the center of the merry-go-round. Calculate Akhila’s centripetal acceleration.
1.923 m/s^2
An airplane flies due south at 197 km/h relative to the air. There is a wind blowing at 68 km/h to the east relative to the ground. What is the plane’s velocity and direction relative to the ground?
208.4 km/h at 71 degrees south of east
A 0.015 kg rubber stopper is attached to a 0.830 m length of string. The stopper is swung in a horizontal circle, making one revolution in 1.08 seconds. Find the velocity of the stopper.
4.82 m/s
A body of mass 10 kg, is moving with a velocity of 5 m/s in a circle of radius 5 m, what is the centripetal acceleration of the body?
5m/s^2
A 5.0 kg object moves in a circle at a constant speed of 10. m/s. What is the radius of the object's circular path if the object's centripetal force is 1000. N?
0.5 m
A plane has a speed of 200 km/h west relative to the air. A wind blows 75 km/h east relative to the ground. What are the plane’s speed and direction relative to the ground?
125 km/h west