1. Questions

Physics

In a relay race, runner A is carrying a baton and has a speed of 3.0 m/s . When he is 25M behind the starting line, runner B starts from rest and accelerates at .10 m/s^2. How long afterwards will A catch up with B to pass the baton to B?

  1. 👍
  2. 👎
  3. 👁
Jami

  1. distance covered by behind runner: 3*t

    distance by starter: 1/2 a t^2

    these times have to be equal,
    so 3t-25=1/2(.1)t^2

    multiply by 20, put in quadratic form
    t^2-60t-500=0

    t= (30-+ sqrt(3600/4 +500))

    = 30 +- 10 sqrt (9+5)
    now for an engneering check:
    let sqrt (15) appx=4
    t=70, or -10 throw out the negative time, we are not going backwards.
    Distance covered by runner: 280
    distance covered by starter: 4900*.05=appx 250 which sounds like a reasonable answer, as runner has to go 25 m further.

    Work it accurately.

    1. 👍
    2. 👎
    bobpursley

Respond to this Question

First Name

Your Response

Similar Questions

  1. Trig/Pre-Calc...

    Please help me with this. The finishing time for a runner completing the 200-meter dash is affected by the tail-wind speed, s. The change, t, in a runner's performance is modeled by the function shown below: t= 0.0119s^2 - 0.308s

  2. Math (fractions)

    I am not being lazy, I've tried to get this done several times, but I am VERY bad when it comes to fractions. Barbara, Donna, Cindy, and Nicole ran in a relay race. Barbara: 3 3/10 Donna: 2 4/5 Cindy: 3 2/5 Nicole: 2 1/10 1. The

  3. Math *fractions*

    Barbara, Donna, Cindy, and Nicole ran in a relay race. Barbara: 3 3/10 Donna: 2 4/5 Cindy: 3 2/5 Nicole: 2 1/10 1. The four girls ran in a relay race as a team. If each girl ran one part of the race, what was the team's total

  4. Physics

    Show how the displacement of a runner changed during a sprint race.draw a displacement-time graph to show this data, and use it to deduce the runner's speed in the middle of the race. Displacement (m) 0 4 10 20 50 80 105, Time(s)

  1. physical science

    during a race a runner runs at a speed of 6 m/s. 2 seconds later she is running at a speed of 10 m/s. what is runners acceleration? show your work.

  2. calculus

    Two runners, A and B run on a straight race track for 0

  3. Physics

    Runner 1 is standing still on a straight running track. Runner 2 passes him, running with a constant speed of 1.5 m/s. Just as runner 2 passes, runner 1 accelerates with a constant acceleration of 0.73 m/s^2. How far down the

  4. Physics-Check

    In a marathon race, one runner is moving at 5.0 m/s passes a second runner moving at 4.5. What is the distance between the runners 10 minutes after the one runner has passed the other? 5m?

  1. math

    The four girls ran in a relay race as a team. Each girl ran one part of the race. The team’s total time was 3 11 5 minutes. What was Cindy’s time

  2. Physics

    The first leg of a relay race is semi circle of diameter 50m. If the runner covers the distance in 11s.calculate the average speed”

  3. math

    Two runners are competing in a race. One runner averages a pace of 7 minutes per mile and finishes the race in 28 minutes. The second runner finishes the race in 30 minutes. Which of the following is the pace of the second runner

  4. Physics

    Running on a treadmill is slightly easier than running outside because there is no drag force to work against. Suppose a 60 kg runner completes a 5.0 km race in 19 minutes. Part A Determine the drag force on the runner during the

You can view more similar questions or ask a new question.