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Math Help - Trucks speed...

  1. #1
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    Trucks speed...

    A truck is accelerating over a certain distance (in metres). Its final speed (v m/s) is related to its starting speed (u m/s), according to the rule v=u+1500. Find the truck's starting and final speeds, given that the truck's final speed is 5 times its starting speed.
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  2. #2
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    Quote Originally Posted by lily123 View Post
    A truck is accelerating over a certain distance (in metres). Its final speed (v m/s) is related to its starting speed (u m/s), according to the rule v=u+1500. Find the truck's starting and final speeds, given that the truck's final speed is 5 times its starting speed.
    Let u denote the starting speed. Then you know that v = 5u

    Plug in this term into the given equation:

    (5u)^2=u^2+1500

    Solve for u. (The negative solution isn't very plausible here)

    Afterwards calculate v.

    I've got v\approx 39.53\ \frac ms. That means the final speed of the truck is 142.3\ \frac{km}h. In Germany the truck driver would be arrested by the police immediately
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