Rock is completely immersed in hot water. By the second law of thermodynamics, thermal energy or heat is transferred from substance with higher temperature to substance with lower temperature until they come to thermal equilibrium i.e. both at same temperature.
It is given here that rock is at 20°C which is at lower temperature than water at 80°C. ∴Heat or thermal energy flows from water to rock. So, right choice is-
A. The water gives the rock thermal energy and gets no thermal energy in return.
Answer:
A. Both spheres land at the same time.
Explanation:
The horizontal motion doesn't affect the vertical motion. Since the two spheres have the same initial vertical velocity and same initial height, they land at the same time.
This phenomenon is as a result of static friction created by the tumbling clothes. Static friction results from the rubbing together of two or mores objects or body and electrons are stripped from one surface of the clothes more than the other. This creates an electrostatic force of attractions between the positive charges on one cloth and the negative charges on the other cloth.(unlike charges attract).
The air inside becomes warmer, and that makes it LESS DENSE.
Less-dense air FLOATS in denser air. Since it's inside the balloon, it picks the balloon up when it floats.
