Question

A handful of professional skaters have taken a skateboard through an inverted loop in a full pipe. For a typical pipe with a diameter of 14 feet (4.27 meters), what is the minimum speed the skater must have at the very top of the loop?

Answer 1

given,

diameter of the pipe is = (14 ft)4.27 m

minimum speed of the skater must have at very top = ?

At the topmost point of the pipe the normal force will be equal to zero.

F = mg

centripetal force acting on the skateboard

`F = (mv^2)/(r)`

equating both the force equation

`mg = (mv^2)/(r)`

`v = √(gr)`

r = d/2 = 14/ 2 = 7 ft

or

r = 4.27/2 = 2.135 m

g = 32 ft/s² or g = 9.8 m/s²

`v = √(32 * 7)`

v = 14.96 ft/s

or

`v = √(9.8 * 2.135)`

v = 4.57 m/s