Answer:
37.5 revolutions
Step-by-step explanation:
The average rotation speed for the first second and for the last two seconds is:
[tex]V_1 = \frac{0+500}{2}\\ V_1 = 250\ rpm[/tex]
For the next 3.0 seconds, the rotation speed is V = 500 rpm.
The total number of revolutions, converting rpm to rps, is given by:
[tex]n=\frac{1*V_1+3*V+2*V_1}{60}\\n=\frac{1*250+3*500*2*250}{60}\\n=37.5\ revolutions[/tex]
The DVD makes 37.5 revolutions.
