Motion in a circle

Question 1

What is s?

Answer 1

Arc length.

Question 2

s = ?

Answer 2

r x theta

Question 3

What angle unit does theta have to be in to find arc length?

Answer 3

Radians.

Question 4

What is the equation to convert from degrees into radians?

Answer 4

Theta rad = theta degrees x π/180

Question 5

Define angular speed?

Answer 5

Rate of change of the angle around the circle with time.

Question 6

What is the equation for angular speed?

Answer 6

ω = theta/t

Question 7

What is T?

Answer 7

Period, time to move through one full circle (2 pi).

Question 8

When t = T and theta = 2π what is ω?

Answer 8

ω = 2πf

Question 9

If angular speed isn’t constant what is ω?

Answer 9

ω = dtheta/dt

Question 10

What is the equation for velocity using ω?

Answer 10

v = rω

Question 11

For a particle traveling in a circle what is constant and what is not constant?

Answer 11

Speed is constant, linear velocity is not.

Question 12

What is the force making an object move in a circle and not fly off in a straight line?

Answer 12

Centripetal force.

Question 13

The centripetal force is what to the direction of motion?

Answer 13

Perpendicular.

Question 14

Magnitude of acceleration, a = ?

Answer 14

-ω^2 x r

Question 15

If an object has net force, it must have what? What is this called?

Answer 15

Must have acceleration, called centripetal acceleration.

Question 16

What is the equation for centripetal acceleration, a?

Answer 16

a = v^2 / r

Question 17

What is the equation for centripetal force, F?

Answer 17

F = mv^2v /r

Question 18

What is an equation for F using ω?

Answer 18

F = mω^2r

Question 19

What are some examples of centripetal force in everyday life?

Answer 19

Earth going around the sun, CF = gravity.

Swinging a ball on a string, CF = tension.