A car initially traveling at 27.2 m/s undergoes a constant negative acceleration of magnitude 1.90 m/s2 after its brakes are applied. (a) How many revolutions does each tire make before the car comes to a stop, assuming the car does not skid and the tires have radii of 0.325 m

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Answer:

Therefore, the revolutions that each tire makes is:

[tex]\Delta \theta=22\: rev[/tex]

Explanation:

We can use the following equation:

[tex]\omega_{f}^{2}=\omega_{i}^{2}-2\alpha \Delta \theta[/tex] (1)

The angular acceleration is:

[tex]a_{tan}=\alpha R[/tex]

[tex]\alpha=\frac{1.9}{0.325}[/tex]

[tex]\alpha=5.85\: rad/s^{2}[/tex]

and the initial angular velocity is:

[tex]\omega_{i}=\frac{v}{R}[/tex]

[tex]\omega_{i}=\frac{27.2}{0.325}[/tex]

[tex]\omega_{i}=83.69\: rad/s[/tex]

Now, using equation (1) we can find the revolutions of the tire.

[tex]0=83.69^{2}-2*25.85 \Delta \theta[/tex]

[tex]\Delta \theta=135.47\: rad[/tex]

Therefore, the revolutions that each tire makes is:

[tex]\Delta \theta=22\: rev[/tex]

I hope it helps you!