The correct option is (A) <span>the first law of thermodynamics
Explanation:
The first law of thermodynamics takes the idea of law of conservation of energy and modify it for thermodynamics systems. It is the total internal energy of the systems equals to the amount of heat added "to" the system and the workdone "by" the system given as:
</span>ΔU = Q - W
<span>Q = heat added TO the system
W = work BY the system
</span>ΔU = Total internal energy
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But the total internal energy is CONSERVED; it means that energy cannot be created or destroyed; it can only be transformed from one form to another. Hence the correct option is (A).</span>
The mass of the boy and skateboard is there to throw you off. X and Y velocities are independent of each other, meaning that the only things you need are the velocity of the skateboard and the velocity of the boy. The total velocity of the boy is 7.5 m/s because the boy would still be moving with the 5 m/s that the skateboard has if the boy were to just jump straight up. Since the boy jumps forward with a velocity of 2.5 m/s, you would add them together.
We use formula, the volume of aluminium
Given, , and
Substituting these values, we get
.
Thus, the thickness of the aluminium foil is 2.55 mm.