Question

Pergunta 5 You need to fill a football with air to play with it. You know that your pump expels air at speed of 8.2 ft/s. The needle of your pump has a radius of 4.5 millimeters. What is the volume flow rate of the air being pumped into the football?

Answer 1

The volume flow rate of the air being pumped into the football will be given by:
 Q=V*A
 Where
 V=Speed
 A=Area
 You know that your pump expels air at speed of 8.2 ft/s
 The area of The needle of your pump is
 A=pi*r^2=pi*((4.5/1000)*(3.28))^2=0.00068442 ft^2
 Finally
 Q=V*A=(8.2 ft/s)*(0.00068442ft^2)=0.005612243 ft^3/s