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 from you in feet after t seconds is given by d= l 100-20 l . At what times is she 40 ft from you?

Question

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  from you in feet after t seconds is given by d= l 100-20 l . At what times is she 40 ft from​ you?

GPT 3.5 · Answer

To find the times when she is 40 ft from you, we need to solve the equation d = 40.

We can rewrite the equation d = l 100-20t l as d = 100-20t.

Substituting d = 40 into the equation, we have 40 = 100 - 20t.

Simplifying the equation, we get 20t = 60.

Dividing both sides by 20, we find t = 3.

Therefore, she is 40 ft from you after 3 seconds.

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 from you in feet after t seconds is given by d= l 100-20 l . At what times is she 40 ft from​ you?

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 from you in feet after t seconds is given by d= l 100-20 l . At what times is she 40 ft from you?