What is the Angular Speed of an Automobile Engine?

[netone]

Homework Statement

. The angular speed of an automobile engine is increased at a constant rate from 140 rad/s to
200 rad/s in 20 s. The number of radians through which the engine turns during this 20-s
interval is

Homework Equations

The Attempt at a Solution

I didnt know where to begin with this question, or know of an equation to start with. so a general hint in the right direction would be very appreciated.

 

[Chestermiller]

Homework Statement

. The angular speed of an automobile engine is increased at a constant rate from 140 rad/s to
200 rad/s in 20 s. The number of radians through which the engine turns during this 20-s
interval is

Homework Equations

The Attempt at a Solution

I didnt know where to begin with this question, or know of an equation to start with. so a general hint in the right direction would be very appreciated.

What's the average speed over the 20 seconds?

 

[netone]

3 rads/s^2

 

[Chestermiller]

That's not the average angular speed. That's the average angular acceleration. What's the average angular speed?

 

[netone]

soo, 170 rads/s then?

 

[Chestermiller]

Sooo, if the average rotational speed is 170 rad/s, and the engine runs for 20 s, how many radians does it rotate through?

 

[netone]

oh ok ,so it would just be 3400 then. Thanks for your help!