**Circular motion**

What is the perfect 'banking angle' for a curve of radius 88 m and speed of 35 m/s?

A train traveling at a constant speed rounds a curve of radius 215 m. A lamp suspended from the ceiling swings out to an angle of 16.5 degrees throughout the curve. What is the speed of the train?

At what minimum speed must a roller coaster be traveling so that passengers upside down at the top of the circle do not fall out? Assume the radius of curvature is 8.6 m

**A coin is placed 13.0 cm from the axis of a rotating turntable. When the speed is slowly increased the coin remains fixed until the rate of 38.0 rpm is reached. What is the coefficient of static friction?**

When a roller coaster is 1/2 of the way through the loop (right at the top) what is the 'net force in the Radial direction'?

A. F (Normal force)

B. F (Force of gravity)

C. F - F

D. F + F

When a roller coaster is all the way through the loop (right at the bottom) what is the 'net force in the Radial direction'?

A. F (Normal force)

B. F (Force of gravity)

C. F - F

D. F + F

When a roller coaster is 1/4 of the way through the loop what is the 'net force in the Radial direction'?

A. F (Normal force)

B. F (Force of gravity)

C. F - F

D. F + F

A conical pendulum (think tether ball) is formed by attaching a 500 g ball to a 1.0 m long string, then allowing the mass to move in a horizontal circle of radius 20 cm. What is the tension in the string? And what is the speed of the ball?

F

F

G

N

O

54.9

25 m/s

5 N

.633 m/s

9.2 m/s

**.21**

"I am still a little confused about the FBD on this section"

"Why does the proper banking of a curve not take into account the mass of a vehicle? In the example in the book mass was used to determine if a car would skid or not."

"the last question on the quiz is confusing to me because i was almost sure i got the answer right"

"How much force must be exerted to a string to spin a block (mass .250 kg) on a frictionless table using a string of length 0.500 m at a speed of 5.00 m/s? (answer should look like '10.6 N')

T

F

G

r

16.5

F

F

N

G

F

G

r

r

**r**

**F**

**F**

**F**

f

G

N

N

N

N

G

G

G

N

N

N

G

G

G

N

N

N

G

G

G