Answer:
The maximum temperature rise = 0.047 °C
Explanation:
Potential Energy, P = mgh
Energy transfered, Q=mcΔT
Potential energy = Energy transfered
mgh = mcΔT
gh = cΔT
ΔT = gh/c
ΔT = (9.81 * 20) / 4186
ΔT = 0.047 °C
Answer:

Explanation:
Since the formula for kinetic energy of an object is:

Where m is the mass of the object and v is the speed. We can substitute m =
kg and v = 17900m/s:

It does take on new set of proerties
If the current takes him downstream we must find the resultant vector of the velocities:

Then if the river is 3000 m-wide the swimmer will have to pass:
1.3520747 · 300 = 4056.14 m t = 4056.14 m : 1 m/s
a ) It takes
4056.15 seconds ( 1 hour 7 minutes and 36 seconds ) to cross the river.
b ) 0.91 · 3000 =
2730 mHe will be 2730 m downstream.