Question

Question #6dda3

Answer 1

v/u = 2

Explanation:

I assume that u is the speed in the first half and v the speed in the last half. Let d be the distance from A to B. Then the distance from A to mid of AB is d/2 and distance from mid of AB to B is also d/2. And let the time to go from mid of AB to B be t. Then the time to go from A to mid of AB is 2*t.

Then `u = ("d/2")/(2*t) = 1/2*d/(2*t) = 1/4*d/t`

and `v = ("d/2")/t = 1/2*d/t`

Therefore, `v/u = (1/2*d/t)/(1/4*d/t) = (1/2*cancel(d/t))/(1/4*cancel(d/t)) = 1/2 * 4/1 = 2`

So, when it goes that distance in half the time, it is going twice as fast!

I hope this helps,
Steve