Answer
Estimate: 60,000; Exact: 84,000
Work Step by Step
To estimate, we round 1400 to the nearest thousand, 1000, and multiply the rounded number of revolutions per minute by the number of minutes:
1000 x 60 = 60,000 revolutions
To find the exact number, we multiply the exact number of revolutions per minute by the number of minutes:
1400 x 60 = 84,000 revolutions