A drilling machine should be set to 250 rpm. The nearest speed available on the machine is 268 rpm. Calculate the percentage over speed.
To calculate the percentage over speed, we need to find out how much the actual speed differs from the desired speed, and then express this difference as a percentage of the desired speed.
The actual speed is 268 rpm, and the desired speed is 250 rpm. The difference between these two speeds is:
268 rpm - 250 rpm = 18 rpm
To express this difference as a percentage of the desired speed, we divide the difference by the desired speed and multiply by 100:
(18 rpm / 250 rpm) x 100 = 7.2%
Therefore, the percentage over speed is 7.2%.