Thread: 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 v²=u²+1500. Find the truck's starting and final speeds, given that the truck's final speed is 5 times its starting speed.

Originally Posted by lily123

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 v²=u²+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

Plug in this term into the given equation:



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

Afterwards calculate v.

I've got . That means the final speed of the truck is . In Germany the truck driver would be arrested by the police immediately