7 the blade on a typical table saw rotates 3450 revolutions

7.

the blade on a typical table saw rotates 3450 revolutions per minute. calculate the linear velocity in miles per hour of one of the teeth at the edge of the 15 inch diameter blade.

the linear velocity is ______ miles per hour. ( round to the nearest tenth as needed)

Solution

Circuference of the blade = pi * diameter

                                         = 3.14 *15

                                         = 47.1 inch

so in one complete revolution of the blade it moves 47.1 inch

so in 1 minute it revolves 3450 times

so in 1 min the total distance = 47.1 * 3450 = 162495 inch/min

now we have to convert in miles/hr                     // 1 mile = 63360 inch

therefore

162495/63360 miles per minute

2.56 miles per minute

now we convert it into miles/hr

we get 2.56/1/60 = 2.56 *60 = 153.6 miles per hour