Unlike record players which rotate at a constant angular velocity, the cd-rom driver in a cd player rotates the cd at different angular velocities so that the optical head maintains a constant tangential velocity relative to the cd. assume the cd has a diameter of 0.120 m and that the cd needs to move at a tangential velocity of 1.26 m/s relative to the optical head so the data (music) can be read correctly. a) what is the angular velocity when the cd-rom is reading data at the outer edge of the cd? give the answer in rpm and rad/s. b) at the inner edge of the cd, the cd-rom rotates at 500 rpm. how far from the center of the cd is the inner edge (vtangential = 1.26 m/s)? c) what is the centripetal (radial) acceleration at the outer edge of the cd? d) what is the rotational frequency (f) of the cd when it is reading data at its outer edge?

A. 21 rad/s

B. 200.5 rpm

C. 26.46 rad/s2

D. 0.299 Hz

Explanation:

Parameters given are:

Tangential velocity,v = 1.26m/s

Diameter (outer edge) = 0.120m

Outer edge radius, ro = 0.12/2

= 0.06m

A. Calculate Angular velocity

Angular velocity, w = v/r

= v/ro

= 1.26/0.06 = 21 rad/s

In rpm,

2pi/60 rad/s = 1 rpm

1 rad/s = 60/2pi rpm

Sp, 21 rad/s = 60 * 21/2pi rpm

= 200.5 rpm

B. Calculate the inner edge radius, ri given w = 500 rpm

Converting rpm to rad/s,

= 2pi/60 * 500 rad/s

= 52.34 rad/s

ri = v/w

= 1.26/ 52.36

= 0.024m

C. Calculating centripetal acceleration, a from the outer edge, ro

a = v2/r = w2r

= (1.26)2/0.06

= 26.46 rad/s

D. Calculate the frequency, f of the outer edge angular velocity, w = 21 rad/s

f = 2pi/w

= 2pi/21

= 0.299 Hz (or per second)

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.