Eileen was 600 feet away from the finish line before the race began.
Step-by-step explanation:
Step 1; Eileen rode at a speed of 20 feet per second whereas Andrew rode at a speed of 15 feet per second. So for every second that passes the distance in between decreases by 5 seconds. Assume x is the number of seconds at which the distance in between is 0. The distance in between at the beginning of the race is 150 feet due to the headstart.
Distance between them = Decreasing distance every second × x
150 feet = 5 feet/ second × x
x = 150 feet / 5 feet/second = 30 seconds.
So it takes Eileen 30 seconds to cover the distance between her and Andrew and cross the finishing line at the same time.
Step 2; The race lasted for 30 seconds so we can find the distance Andrew and Eileen traveled by multiplying their speed per second with the total number of seconds.
Distance Andrew traveled = speed per second × total number of seconds
= 15 feet per second × 30 seconds = 450 feet
Distance Eileen traveled = speed per second × total number of seconds
= 20 feet per second × 30 seconds = 600 feet
Graph plot;
The X-axis is time with 5 seconds for each cm
the y-axis is distance with 100 feet for each cm.
Eileen's plot (0,0), (5,100), (10,200), (15,300), (20,400), (25,500), (30,600).
Andrew's plot (0,150), (5,225), (10,300), (15,375), (20,450), (25,525), (30,600).
