Water flows over a fall that is 125.0 m high. If the potential energy of the water is all converted to thermal energy, calculate the temperature difference between the water at the top and the bottom of the fall.

ΔT = 0.29°C

Explanation:

Using the law of conservation of energy:

where,

ΔT = Temperature difference between the water at the top and the bottom of the fall = ?

g = acceleration due to gravity = 9.81 m/s²

h = height of fall = 125 m

C = specific heat capacity of water = 4200 J/kg

Therefore,

ΔT = 0.29°C

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form