Question

You pull your car into your driveway and stop. The drive shaft of your car engine, initially rotating at 2400 rpm, slows with a constant rotational acceleration of magnitude 30 rad/s2.

Answer 1

Complete question is: You pull your car into your driveway and stop. The drive shaft of your car engine, initially rotating at 2400 rpm,slows with a constant rotational acceleration of magnitude 30 rad/s². How long does it take for the drive shaft to stop turning?

Answer:

8.37 s

Step-by-step explanation:

Initial rotational velocity, ω₀ = 2400 rpm = 2400 × 2π/60 = 251.2 rad/s

Final velocity, ω = 0

rotational deceleration, α =- 30 rad/s²

Use the first equation of rotational motion:

`t = (\omega - \omega_o)/(\alpha)`

Substitute the values:

`t = (0 - 251.2)/(-30)=8.37 s`