A bottle of water at a room temperature of 21.0 C is placed into a refrigerator with an air temperature of 4.5C. The thermal energy will move — *

A. from the cooler air to lower the temperature of the water to 4.5 C

B. in both directions until the temperature is equal in the water and the air

C. from the water to the air until the water temperature is zero degrees Celsius

O D. from the water to the air until the temperature is equal in both

B. in both directions until the temperature is equal in the water and the air

Explanation:

When a warm body is in contact with a cool body , there is exchange of heat energy in both sides until there is attainment of equilibrium temperature . At this temperature both the body attains equal temperature . Initially rate of heat radiated by warm body is more than that from cool body , but after attainment of equilibrium , the rate becomes equal to each other . This is called dynamic equilibrium .

Hence option B is correct .

it doesn't. it was imagined up in the middle ages.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.