Question

A drive has a maximum speed of 10000 revolutions per minute. If a disc has a diameter of ​12 cm what is the linear​ speed, in​ km/h, of a point 4cm from the center if the disc is spinning at a rate of 7000 revolutions per​ minute?

Answer 1

10.8 km/hr

Explanation:

Given that

radius of the diameter is 4 cm

Converting 4 cm to km, we have

4/100000 = 0.00004 km or 4*10^-5 km

Angular speed is given as

v = 2πr/T

Where T is, 1/n,and n is the number of revolutions

v = (2 * 3.142 * 0.00004) / (1/7000)

v = 0.00126 / 0.007

v = 0.18 km/min

This is in km/min, now we convert to km/hr as requested.

0.18 * 60 = 10.8 km/hr