UCM and Torque Review

• Your physics teacher is spinning a cup of water around their head at the end of a string that is 0.8 m long. Assuming they can spin it at 3 revolutions per second, what is the tangential velocity of the cup?

• If your physics teacher was spinning a 0.25 kg cup around their head on the end of a 0.5 m long rope with a tangential velocity of 2 m/s, what would the centripetal acceleration be?

• What is torque and how can you calculate it?

• What explains why an object traveling in uniform circular motion will move tangent to that circular path if the centripetal force is removed?

• Suppose a 985 kg racecar is traveling at 250 m/s down the straight side of a track. How much centripetal force is required to keep that racecar on the track if the radius of the curved end of the track is 125 m.

• A ball is whirled in a horizontal circle of radius r, speed v and acceleration a.

• The velocity is increased to 2v. The acceleration of the ball is:

• A ball is whirled in a horizontal circle of radius r, speed v and acceleration a.

• The period is increased to 2T. The velocity of the ball is:

• A ball is whirled in a horizontal circle of radius r, speed v and acceleration a.

• The radius is increased to 2r. The velocity of the ball is:

• A child standing on a merry go round has a tangential velocity of 4 m/s and makes a complete revolution every 3 seconds. What is the radius of the merry go round?

• A top spins with an acceleration of 8 m/s2. If the top has a radius of 0.3 m, what is the tangential velocity a sticker on the top?

• An a salt shaker on a lazy Susan with a radius 0.4 m makes 36 revolutions in 18 seconds. What is the centripetal acceleration of the salt shaker?

• A dog of mass 85 kg spins in a circle as it chases his tail. If he has a radius of 0.8m and makes a complete circle in 1.3 s, how much centripetal force does he required?