Hey.. ♥️♥️ me in solving this question

Let Vb = the velocity of the boat.

Vw = the velocity of the flow of the stream.

X = the distance the boat traveled downstream.

So X = (Vb+Vw)T

After turning, the boat takes t time to get back to the float.

Then x -l = (Vb-Vw)t

and l = Vw * (T+t)

Replacing the equations for their variables you get (Vb+Vw)T-Vw(T+t) = (Vb-Vw)t

Simlify to: Vw = l/T+t = l/2T

Now using the values in the problem:

Vw = 12km / 2 * 60 = 12 km / 2hrs = 6km

The answer is 1. 6 km h^-1

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.