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
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:
[tex] t = \frac{\omega - \omega_o}{\alpha}[/tex]
Substitute the values:
[tex] t = \frac{0 - 251.2}{-30}=8.37 s[/tex]
