Starting from 100 ft away, your friend skates toward you and then passes you. She skates at a constant speed of 20 ft/s. Her distance d = l100-20tl from you in feet after t seconds is given by d. At what times is she 20 ft from you?
To find the times when she is 20 ft from you, we need to solve the equation d = 20 ft.
Given that d = 100 - 20t, we substitute this into the equation:
100 - 20t = 20
Rearranging the equation, we have:
20t = 100 - 20
20t = 80
Dividing both sides by 20, we have:
t = 4
So, she is 20 ft from you after 4 seconds.
To find the times when your friend is 20 ft away from you, we can set up an equation and solve for t.
According to the given information, the distance (d) between you and your friend at any given time (t) is given by the equation:
d = 100 - 20t
We want to find the times when she is 20 ft away from you. So, we can replace d with 20 in the equation and solve for t:
20 = 100 - 20t
To solve for t, we need to isolate the variable t. Let's rearrange the equation:
20t = 100 - 20
20t = 80
Now, divide both sides of the equation by 20 to get t:
t = 80 / 20
t = 4
So, your friend is 20 ft away from you at t = 4 seconds.
To find the times when your friend is 20 ft from you, we need to set up an equation using the given distance function.
The distance equation is:
d = 100 - 20t
To find when your friend is 20 ft from you, we set d = 20 and solve for t.
Substituting the value of d = 20 into the equation:
20 = 100 - 20t
Rearranging the equation:
20t = 100 - 20
Simplifying:
20t = 80
Dividing both sides by 20 to solve for t:
t = 80/20
Simplifying further:
t = 4
Therefore, your friend is 20 ft from you at t = 4 seconds.