# Forces Affecting a Bicycle

In Glogpedia

by Chewie11
Last updated 8 years ago

Discipline:
Science
Subject:
Forces & Motion
7

Gear ratiosGear ratios are ratios that show the number of teeth two interlocking gears. For example in 1A, the gear ratio is 60:30 or 2:1. Gear B is going twice the speed of gear A because is has only half the number of teeth. If the gear ratio were to be 90:30 (3:1) then one of the gears would go 3 times as fast as the other one.

Forces and simple machines

These are the points of friction. Friction is a contact force that occurs when two surfaces rub together (like the tyres and the road). There are two things that affect friction- mass and surface area. The greater that these things are, the more friction there will be. For example rock climbers put resin on their hands, increasing the surface area and therfore the friction.

The thing I have chosen for my Science assignment is a bicycle. I'm going to explain the different forces and simple machines that are involved.The knoledge of forces and simple machines has helped cyclists to go faster and cycle for longer. If we had not known about friction or air resistance, our bikes today might be less streamlined or have thicker tyres (which creates more friction). Simple machines like gears have also helped the human race by allowing us to go faster or power easily up hills.In the future, our bikes might have even more gears or we might find a way to make them frictionless but we can only guess what will happen at the moment.

GearsThe main simple machine in a bicycle is probably the gears. Gears will either reduce the force needed to pedal but make the bike go slower or increase the force needed to pedal but make accelerate faster. This is because of gear ratio.

The ground is holding the bike up. If the force of gravity is greater than the force of the ground (eg. the bike is on a thin sheet of ice) the bike will fall through it.

There are many different types of friction but the main ones are:-Normal friction (solids rubing against solids) -Air resistantce (solids rubing against gas or air)-Water friction (solids rubbing against liquids)

Power in this picture refers to the force that the guy is pushing the pedals with. If this force is less than that of gravity pulling the bike down the hill, than he will go backwards down the hill

The forces affecting a bicycle