#### Transcript of LPH 105 W15 8:1-3

My new router bit can only be used at speeds less than 6500 rpm. If it takes 10 s to get up to this speed, what is the angular acceleration? How many revolutions does it make in that time?

A child rolls a ball on a level floor 3.5 m to another child. If the ball makes 12.0 revolutions, what is its diameter?

A bicycle with tires 68 cm in diameter travels 9.2 km. How many revolutions do the wheels make?

A grinding wheel 0.35 m in diameter rotates at 2200 rpm. Calculate its angular velocity in rad/s. What are the linear speed and acceleration of a point on the edge of the grinding wheel?

** Calculate its angular acceleration**

**An automobile engine slows down from 3500 rpm to 1200 rpm in 2.5 s.**

**The total number of revolutions the engine makes in this time.**

How long did it take the fan to come to a complete stop?

What was the fan's angular acceleration?

A cooling fan is turned off when it is running at 850 rev/min. It turns 1250 revolutions before it comes to rest

A wheel 31 cm in diameter accelerates uniformly from 240 rpm to 360 rpm in 6.8 s.

How far will a point on the edge of the wheel have traveled in this time?

and the time it takes the pottery wheel to reach its required speed of 65 rpm

Calculate the angular acceleration of the pottery wheel

A small rubber wheel is used to drive a large pottery wheel. The two wheels are mounted so that their circular edges touch. The small wheel has a radius of 2.0 cm and accelerates at the rate of 7.2 rad/s^2, and it is in contact with the pottery wheel (radius 27.0 cm) without slipping

681 rad/s

68.1 rad/s^2

542 revolutions

9.28 cm

4300 revolutions

230 rad/s

40 m/s

9290 m/s^2

**-96 rad/s^2**

**98 revolutions**

-.504 rad/s^2

176 s

"it is difficult for me to distinguish between angular acceleration, angular velocity. could you explain that to me better?"

"tangential vs centripetal vs total (acceleration)"

"Can you just explain Inertia again?"

"I don't understand how center mass velocity equals tangential velocity when something is rolling,"

"I'm having a hard time understanding the relationship between linear and rotational quantities."

"what does the 2pi thing mean that we sometimes use in conversions?" " I'm still pretty confused with the concept of radians"

"If a merry-go-round is rotation at a constant speed of 75.0 rpm, how many RADIANS will it go through in 20.0 seconds? (answer should look like '123 radians' )"

33 m

.533 rad/s^2

12.8 s

219

8-20

What have they given us, and what are they asking for?

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