An astronaut is being tested in a centrifuge. The centrifuge has a radius of 9 m and, in starting, rotates according to ? = 0.30t2, where t is in seconds and ? is in radians.


(a) When t = 9.0 s, what is the magnitude of the astronaut's angular velocity?

(b) When t = 9.0 s, what is the magnitude of the astronaut's linear speed?

(c) When t = 9.0 s, what is the magnitude of the astronaut's tangential acceleration?

(d) When t = 9.0 s, what is the magnitude of the astronaut's radial acceleration?

Answer :

Answer:

5.4 rad/s

48.6 m/s

5.4 m/s²

262.44 m/s²

Explanation:

r = Radius of centrifuge = 9 m

[tex]\theta=0.3t^2[/tex]

Differentiating with respect to time

[tex]\frac{d\theta}{dt}=0.6t=\omega[/tex]

At t = 9 s

[tex]\omega=0.6\times 9=5.4\ rad/s[/tex]

Angular velocity is 5.4 rad/s

Linear speed

[tex]v=r\omega\\\Rightarrow v=9\times 5.4=48.6\ m/s[/tex]

The linear speed of the astronaut is 48.6 m/s

Differentiating [tex]\omega[/tex] with respect to time

[tex]\frac{d\omega}{dt}=0.6=\alpha[/tex]

Tangential acceleration is given by

[tex]a_t=\alpha r\\\Rightarrow a_t=0.6\times 9=5.4\ m/s^2[/tex]

Tangential acceleration of the astronaut is 5.4 m/s²

Radial acceleration is given by

[tex]a_r=\frac{v^2}{r}\\\Rightarrow a_r=\frac{48.6^2}{9}\\\Rightarrow a_r=262.44\ m/s^2[/tex]

The radial acceleration of the astronaut is 262.44 m/s²

Other Questions