Transcript UCM and Torque Review

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?