# Speed and accleration of a turntable

1. Mar 4, 2008

### clope023

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

An electric turntable 0.740m in diameter is rotating about a fixed axis with an initial angular velocity of 0.290rad/s . The angular acceleration is 0.900rad/s^2 .

a) Compute the angular velocity after a time of 0.194s. - .465rev/s

b) Through how many revolutions has the blade turned in this time interval? - .073rev

c) What is the tangential speed of a point on the tip of the blade at time t = 0.194s ?

d) What is the magnitude of the resultant acceleration of a point on the tip of the blade at time = 0.194 ?

2. Relevant equations

v = r$$\omega$$

arad = $$\omega$$^2r

atan = r$$\alpha$$

3. The attempt at a solution

for part c)

v = (.740/2)(.465) = .172m/s wrong

for part d)

atan = (.740/2)(.900) = .333m/s^2

a = (.0800^2 + .333^2)^(1/2) = .342m/s^2 wrong

I'm not sure what I'm doing wrong, any help is appreciated.

2. Mar 5, 2008