Thermal Conductivity

In keeping with the theme of material properties from the last post, today we’ll talk about thermal conductivity which is a material property that relates to the conduction of heat.

Specific Heat: cp and cv

Earlier, we looked at the specific heat ratio, and we also looked at the variation in specific heat with temperature here and here. Today we’ll look in a little more detail at the properties constant volume and constant pressure specific heat.

Bicycling Downhill

We’ve been talking here and here about the effects of weight, speed, and grade on climbing hills on a bicycle.  Now, let’s reverse direction and think about coasting down a hill. 

More Bicycling Uphill

Last time we looked at how weight and speed and grade affect the power requirement for a bicyclist climbing a hill.  Today, we’ll reverse the question and assume that the cyclist has a fixed amount of power to deliver.  How will that affect climbing speed?

Bicycling Uphill

Not long ago I was huffing and puffing on my bicycle up a very steep hill and another cyclist blew by me with apparently little effort.  Now, in addition to looking younger, stronger, and having a better bicycle, he appeared to be carrying significantly less excess, ahem, baggage.  So I got to wondering how much difference one’s weight (or to be charitable, a loaded backpack) makes when ascending a hill on a bicycle.

Cheeseburgers per hour?

In the last two posts, we considered the units of food energy, and some of the issues associated with calculating human energy use. Today we’ll look at different views of calculating energy use from exercise.

Cheeseburgers per day?

Last post we talked about the units used for describing the energy content of food.  For the purposes of an energy balance on the body, we also have to consider the efficiency of converting food energy into activity.