# Lewis Howard Latimer Student Worksheet

### Historical Connection

What were some of the personal and cultural difficulties that Latimer faced in his life? Why do you suppose that Latimer did not let the difficulties that he faced in his life keep him from making something out of himself? How did he overcome the difficulties?

### Math and Science Connections

Despite personal and cultural obstacles, Latimer learned and used mathematics to make his discoveries and inventions in the science of electricity (the flow of electrons from one point to another). Without mathematics, no electrical appliance would exist.

Using the formula Energy = Power x Time a 40-watt light bulb generates 69,000 calories of heat energy in two hours. This is equal to the heat energy (calories) in one month of food.

Another formula deals with how brightly a light is shining. The intensity or brightness of the light coming from an electric lamp or any other source of light is inversely proportional to the square of the distance from the source. This relationship is expressed by the following formula:

### I = K/D^2

In this formula, I is the intensity of the light in a unit called lumens, D is the distance from the light source in meters, and K is the constant of variation.

Use the formula above to complete the table using K = 3200.

Distance from Light Source
in Meters
Intensity of Light
in Lumens
1
2
3
4

What pattern do you see developing?

Graph the relationship on graph paper using distance as the x-axis and intensity as the y-axis.