A wheel rotating about a fixed axis has a constant angular ...

[penguins]

A wheel rotating about a fixed axis has a constant angular acceleration of 4.0 rad/s2 . In a 4.0-s interval the wheel turns through an angle of 80 radians. Assuming the wheel started from rest, how long had it been in motion at the start of the 4.0-s interval?
 a. 2.5 s
  b. 4.0 s
  c. 3.5 s
  d. 3.0 s
  e. 4.5 s

Question 2

A wheel starts from rest and rotates with a constant angular acceleration about a fixed axis. It completes the first revolution 6.0 s after it started. How long after it started will the wheel complete the second revolution?
 a. 9.9 s
  b. 7.8 s
  c. 8.5 s
  d. 9.2 s
  e. 6.4 s

[meganlapinski]

Answer to Question 1

D

Answer to Question 2

C