(a) What is the tangential acceleration of a bug on the rim of a 6.0 in. diameter disk if the disk moves from rest to an angular speed of 79 rev/min in 5.0 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?

What is its total acceleration?

° (relative to the tangential acceleration)

I don't understand how to go from the rad/s to meters/s and all of that.

for the first one, I changed the rev/s to rad/s which was 8.275 rad/s and then i divided that by 5s to get the angular acceleration and then mulitiplied it by the radius (.1524m) in order to change it to tangential acceleration but it said my answer was incorrect.

also, i just looked at it and i believe the answer gives me the wrong units anyways, so I think that is where I am messing up.

1 answer

I get an angular velocity after 5.0 seconds of 8.273 rad/s. The angular acceleration is 1.655 rad/s. The three inch radius is 0.0762 meters. I believe yu confused the diameter with the radius.

The tangential velocity after 5 seconds is the radius times 8.273 rad/s