When two quantities x and y are proportional, the relationship can be represented by the equation y=mx.
B
Use the equation obtained in Part A.
A
Yes, see solution.
B
4116 meters
Practice makes perfect
We can see a lightning strike and hear thunder 12 seconds later. We want to know if there is a proportional relationship between the amount of time that passes and our distance from the lightning strike. To do so, remember that when two quantities are proportional, the relationship can be represented by the following equation.
y=mxNow, let's recall the formula for the speed.
s=d/t
Here, d is the distance traveled and t is the time. Since we want to find the relationship between distance and time, we need to solve this equation for d.
Note that this equation has the same form as the proportional relationship. Therefore, there is a proportional relationship between the amount of time that passes and your distance from the lightning.
We want to estimate our distance from the lightning strike. To do so, recall the equation obtained in Part A.
d=st
Consider that the speed of sound in air is 343 meters per second. Since we can hear the thunder 12 seconds after seeing the lightning, we can substitute s= 343 and t= 12 into the above formula to calculate our distance from the lightning strike.
