Finding the number of revolutions for an car in an angular system

[tyro008]

Homework Statement

The angular speed of an automobile engine is increased at a constant rate from 1500 rev/min to 3900 rev/min in 14 s.
(A) What is its angular acceleration in revolutions per minute-squared?

(B) How many revolutions does the engine make during this 14 s interval?

Homework Equations

I found out (A) to be 10285.71429 rev/min^2, but I have no idea how to do (B). would have to find tangential velocity or do i have enough information already?

The Attempt at a Solution

for (A), i used the formula \alpha = \Delta\omega / time
so (3900rev/min - 1500rev/min)/14,
and this was 10285.71420rev/min^2
i just don't know how to start (B)..

 

[tyro008]

oh sorry, the alpha stands for angular acceleration
the delta of little omega stands for change in anuglar speed :]

 

[tyro008]

whoops, change in angular* speed