Aplastic-foam container used as a picnic cooler contains a block of ice at 0°c. if 225g of ice melts, how much heat passes through the walls of the container?

18kcal

Explanation:

Melting enthalpy of water: 80 cal/g

The melting enthalpy discribes how much heat is needed to melt a substance. So you get the heat by multiplying the mass of your substance with its melting enthalpy.

225g*18cal/g=18000cal=18kcal

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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