You have a friend who just bought a new car. He wants to show you how fast it ca

Question

You have a friend who just bought a new car. He wants to show you how fast it can accelerate, so he takes you and the car to a local drag strip. (A drag strip is a race track that is short, straight and flat.) He asks you to measure the time that it takes him to travel from one end of the drag strip to the other, beginning from a standing start. You plan to use the stop watch on your smart phone to measure his time. At the moment he starts his run, however, you realize that you have left your phone in his car. After the race, he tells you that his final speed was 113 miles per hour The accelerometer on your smart phone says that his average acceleration was 0.002 miles / second2 How long did it take him to run his race? Your answer should be accurate to the nearest 0.1 second. Hints: Convert the final speed to miles per second before doing your calculation. You do not need to know the length of the drag strip to calculate the answer.

Explanation / Answer

speed v = 113 miles/hour = (113/3600) miles per second

speed v = 0.031389 mps

average acceleration a = 0.002 miles/second2

Time t = v/a

t = 0.031389 / 0.002

t = 15.69 s

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.