<u>Answer</u>
A. Metals A and metals B
<u>Explanation</u>
Heat transfer takes place whenever there is temperature difference. When two bodies of different temperatures are brought together, heat energy will move from one body to the other until equilibrium temperature is reached.
In our case, heat transfer will take place in all four metals.
Metal A will transfer heat to the water since it's temperature is higher than that of water.
Metal B will also transfer heat to the water since it's temperature is higher than that of water.
Metal C will get heat from the water since it's colder than the water.
Metal D will also get heat from the water since it is colder than water.
Answer:

Explanation:
The system ball-pin is modelled by the Principle of Moment Conservation:

The velocity of the bowling ball after the collision is:

Answer:
The value we are given in the question is 1.24 * 10^7. This form of writing number is called scientific notation. The standard notation is the normal, regular way of writing numbers. Scientific notation and standard notations are interchangeable.
1.24 * 10^7 written in standard notation will be = 1.24 * 10000000 = 12400000.
Thus, the mass of the meteoroid was 12400000 kg.
Explanation: