## anonymous 4 years ago The crankshaft in a race car goes from rest to 3540rpm in 2.6s. What is the crankshaft's angular acceleration? How many revolutions does it make while reaching 3540rpm?

1. 3psilon

use $\omega = \omega _o + \alpha t$ $\omega_o= 0$ since it starts from rest. so $\omega = \alpha t$ solve for alpha$\alpha=\frac{ \omega }{ t }$ Now just plug in and solve. Also I'm assuming your answer should be in radians/sec? $\frac{ 3540rev/m }{ 2.6\sec } * \frac{ 2\pi }{ 1 rev }*\frac{ 1 \min }{60 \sec } = 142.58 rad/s^{2}$

2. 3psilon

For the second part use the angular displacement formula $\Delta \theta = \omega _o +\frac{ 1 }{ 2 } \alpha t^{2}$ and just plug in (note it starts from rest so omega initial = 0)

3. anonymous

Nice @3psilon

4. 3psilon

Make sense @Ashley1593

5. 3psilon

?

6. anonymous

yes thank you