The car is stopped at a red light. When the light turns green, the car begins moving forward. The distance in feet of the car from the light after t seconds is given by the equation D = 4t ^ 2

Question

how far is the car from the light after 5 seconds.

how far is the car from the light after 10 seconds.

how far is the car from the light at t = 0 seconds explain.

Answer 1

Hello! my name is Saragrace. Okay so when looking at the question the most important pieces on information are when the letters in the equation stand for. So the D stands for Distance from the light and t, stands for seconds, which we know from the question.

First question:

So if we want to know how far the car is from the light after 5 seconds and t stands for seconds we will just plug in 5 where t is and solve for D.

D = 4t^ 2

D = 4(5) ^2

D = 400

400 feet from the light after 5 seconds

Second Question:

Since we are just looking at the equation with a different about of seconds you do that same process with the new number.

D = 4(10)^ 2

D = 1,600

1,600 feet from the light after 10 seconds

Last question:

plug is 0 for t and solve

D = 4(0)^2

D = 0

This makes sense though right? because if you are 0 seconds from the light Then you have not moved at all. So your answer should be 0 because you have moved 0 feet.

Answer 2

after 5 seconds the car is 100 ft and after 10 seconds its 400 ft. See my work above

at t=0 it is 0 ft away