Answer:
3.8 in
Explanation:
A wheel and axle machine is a machine in which the wheel rotates around the rod (axle). They rotate together thereby transferring force among each other.
The formula for a wheel and axle is:
Fr * Rr = Fe * Re
Where Fr is the resistance force, Rr is the radius of the resistance force, Fe is the effort force and Re is the radius of the resistance force.
Given that: Fr = 235 lb, Fe = 45 lb, Re = 20 in / 2 = 10 in. Hence:
235 * Rr = 45 * 10
Rr = 45 * 10 / 235
Rr= 1.9 in
Diameter of axle = 2 * 1.9 = 3.8 in
