The quantity of heat must be removed is 1600 cal or 1,6 kcal.
<h3>Explanation : </h3>
From the question we will know if the condition of ice is at the latent point. So, the heat level not affect the temperature, but it can change the object existence. So, for the formula we can use.

If :
- Q = heat of latent (cal or J )
- m = mass of the thing (g or kg)
- L = latent coefficient (cal/g or J/kg)
<h3>Steps : </h3>
If :
- m = mass of water = 20 g => its easier if we use kal/g°C
- L = latent coefficient = 80 cal/g
Q = ... ?
Answer :

So, the quantity of heat must be removed is 1600 cal or 1,6 kcal.
<u>Subject : Physics </u>
<u>Subject : Physics Keyword : Heat of latent</u>
Answer:
Explanation:
a ) from San Antonio to Houston let distance be d km .
Average speed = total distance / total time
time = distance / speed
Total time = (d / 2 x 75 ) +( d / 2 x 106 )
= .0067 d + .0047 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
b ) from Houston back to San Antonio
Total time = (d / 2 x 106 ) +( d / 2 x 75 )
= .0047 d + .0067 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
c )
For entire trip :
total distance = 2d
total time = 2 x .0114 d
Average speed = 2 d / 2 x .0114 d
= 87.72 km /h .