As a result of friction, the angular speed of a wheel c hanges with time according to d θ d t = ω0 e −σ t , where ω0 and σ are constants. The angular speed changes from an initial angular speed of 4.43 rad/s to 3.63 rad/s in 3.92 s. Determine the magnitude of the angular acceleration after 3.41 s. Answer in units of rad/s 2 .

Respuesta :

Answer:

The value of angular acceleration after 3.41 s is -0.18925 rad/s^2

Step-by-step explanation:

As per the given data the value is given as

[tex]\frac{d\theta}{dt}=\omega_oe^{-\sigma t}[/tex]

Where

  • [tex]\omega_o[/tex] is given as 4.43 rad/s
  • [tex]\sigma[/tex] is calculated as follows

[tex]3.63=4.43 e^{-\sigma *3.92}\\e^{-\sigma 3.92}=\frac{363}{443}\\-\sigma \cdot \:3.92\ln \left(e\right)=\ln \left(\frac{363}{443}\right)\\\sigma=0.05080[/tex]

Now as the acceleration is given as

[tex]\alpha=\frac{d}{dt}(\frac{d\theta}{dt})\\\alpha=\frac{d}{dt}(\omega_oe^{-\sigma t})\\\alpha=\omega_o\frac{d}{dt}(e^{-\sigma t})\\\alpha=-\omega_o \sigma(e^{-\sigma t})[/tex]

As  values of

  • [tex]\omega_o[/tex] is given as 4.43 rad/s
  • [tex]\sigma[/tex] is calculated as 0.05080
  • t is 3.41

thus acceleration is given as

[tex]\alpha=-\omega_o \sigma(e^{-\sigma t})\\\alpha=-4.43*0.05080(e^{-0.05080* 3.41})\\\alpha=-0.18925\, rad/s^2[/tex]

So the value of angular acceleration after 3.41 s is -0.18925 rad/s^2