# What is its centripetal acceleration?

1. Jun 30, 2010

### mandy9008

1. The problem statement, all variables and given/known data
(a) What is the tangential acceleration of a bug on the rim of a 8.0 in. diameter disk if the disk moves from rest to an angular speed of 77 rev/min in 3.0 s? (b) When the disk is at its final speed, what is the tangential velocity of the bug? (c) One second after the bug starts from rest, what is its tangential acceleration? What is its centripetal acceleration?

2. Relevant equations
ac= vT2 / R

3. The attempt at a solution
I got all of the answers in italics, I just can;t figure out the bold part.
a. a=0.273 m/s2
b. vT=0.819 m/s
c. a=0.273 m/s2

d. ac = 0.819 m/s 2 / 0.1016
ac = 6.60 m/s2

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jun 30, 2010

### Staff: Mentor

It's not clear to me what you did here. How do you calculate the centripetal acceleration? Hint: What's the speed of the bug at the point in question?

3. Jun 30, 2010

### mandy9008

i used the equation: ac= vT2 / R

4. Jun 30, 2010

### Staff: Mentor

OK, good. What's the speed of the bug after one second? (Note that this is not the final speed you calculated in part b.)

5. Jul 1, 2010

6. Jul 1, 2010