A particular disc can be made to rotate at 2 different speeds. If it were made to rotate slower by 135 revolutions per hour, it would require an additional 2.7-hour to make 315 revolutions. Find the higher speed at which it can operate.
A particular disc can be made to rotate at 2 different speeds. If it were made to rotate slower by 135 revolutions per hour, it would require an additional 2.7-hour to make 315 revolutions. Find the higher speed at which it can operate.
let $\displaystyle \omega$ be the higher speed of rotation in rev/hr
$\displaystyle t$ = time in hrs to rotate 315 rev at the higher speed
$\displaystyle \omega t = 315$
$\displaystyle (\omega - 135)(t+2.7) = 315$
solve the system of equations for $\displaystyle \omega$ ... I'd start by using the first equation and solving for $\displaystyle t$ in terms of $\displaystyle \omega$, then substitute for $\displaystyle t$ in the second equation.