Question

A battery with 20%20%20, percent of its full capacity is connected to a charger. Every minute that passes, an additional 5%5%5, percent of its capacity is charged.Graph the battery's capacity (in %%percent charged) as a function of time (in minutes).

Answer 1

You have to determine the relationship between the charge percentage of the battery and the time it is charging.

y represents the charge percentage.

x represents the time the battery is being connected to the charger.

When the battery is connected to the charger (time zero) it has 20% of the battery, this percentage represents the y-intercept of the line.

The charging rate is 5% per minute, this means that every minute the battery charge increases 5% → this value represents the slope of the line.

So the equation for the line is

`y=5x+20`

To plot the line you have to determine two points of it: for example the y-intercept (0,20)

And another point can be the charge after 2 minutes have passed

For x=2min

y=5*2+20

y=30%

The second point is (2,30)