Ask Question
21 March, 14:39

As a runner crosses the finish line of a race, she starts decelerating from a velocity of 9 m/s at a rate of 2 m/s^2. Take the runner's velocity as she crosses the finish line to be in the positive direction. What is the runner's displacement, in meters, during the first 5 seconds after crossing the finish line?

What is her velocity, in meters per second, 5 seconds after crossing the finish line?

+4
Answers (1)
  1. 21 March, 17:14
    0
    - 1 m/s, 20 m

    Explanation:

    u = 9 m/s, a = - 2 m/s^2, t = 5 sec

    Let s be the displacement and v be the velocity after 5 seconds

    Use first equation of motion.

    v = u + a t

    v = 9 - 2 x 5 = 9 - 10 = - 1 m/s

    Use second equation of motion

    s = u t + 1/2 a t^2

    s = 9 x 5 - 1/2 x 2 x 5 x 5

    s = 45 - 25 = 20 m
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “As a runner crosses the finish line of a race, she starts decelerating from a velocity of 9 m/s at a rate of 2 m/s^2. Take the runner's ...” in 📘 Physics if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers