A Compound Machine: The Bicycle Sph4c (Page 4 of 4) in pdf

A Compound Machine: The Bicycle Sph4c Page 4

Determine the AMA for the lowest gear ratio and for

the highest gear ratio by tying a piece of string

around the tire (as shown in the diagram at right) to

measure the load force.

(You will need to hold both spring scales.)

Vary the load force and record the measurement on

both spring scales when you are holding both at

static equilibrium.

Table 1: Load force and effort force for the lowest gear ratio

Load Force F

Effort Force F

Trial

(N)

AMA=

Calculate your average AMA for the lowest gear ratio: average AMA = ____________

Determine the percent efficiency of the lowest gear ratio:

AMA

percent efficiency =

x 100% =

IMA

Could this percent efficiency change when the bicycle is in motion? Explain.

____________________________________________________________________________

Table 2: Load force and effort force for the highest gear ratio