Physics of Mountain Biking on weebly.com

I’d be tempted just to leave this one alone because it looks like a high school physics weekend project, but this kind of site, with its attractive pictures and simple text, is just the kind of place high school physics students might be tempted to get their information.

The section on Newton’s 1st law contains this gem

When the brakes are applied, the force of friction increases due to the increase in rolling coefficient of friction. This unbalanced force is what brings the bike to rest demonstrating Newton’s first law.

Yes, the brakes generate friction, which convert kinetic energy to heat energy to be dissipated, but this has nothing to do with the increase in rolling coefficient of friction, whatever that might be. And the deceleration due to braking is an example of Newton’s 2nd law,  not 1st.

Then, in the section on Newton’s 2nd law, we get this nonsense

As you can see from the equation, net force is proportional to its mass. If you double the mass, then the net force doubles as well.

Sure, if acceleration is kept constant, but you have to say that for the above to be true.

Finally, in the section on Newton’s 3rd law,

Additionally, the suspension of mountain bikes uses the principal of Newton’ third law. Riding over rough terrain of several bumps and depressions, suspension systems on mountain bike transform the reaction force more into the bike itself instead of into the rider.

If you can make sense out of this, let me know.

I guess this is what we get from anonymous content providers.

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