Energy from the sun reaches Earth by
A
conduction and convection.
B
radiation only.
C
conduction only.
D
conduction and radiation.
B
radiation only.
The correct answer is B) radiation only. Energy from the sun reaches the Earth through a process called radiation. Radiation refers to the transfer of heat energy in the form of electromagnetic waves. These waves travel through space and do not require a medium like air or water to transfer the heat.
The correct answer is B) radiation only.
To understand why radiation is the primary method by which energy from the sun reaches Earth, we need to understand the different mechanisms of heat transfer.
Conduction is the transfer of heat through direct contact between objects. This involves the transfer of energy from vibrating particles in a solid to adjacent particles. For example, when you touch a hot pan, heat is conducted from the pan to your hand.
Convection, on the other hand, is the transfer of heat through the movement of fluids (liquids or gases). This occurs when warmer, less dense fluids rise and cooler, denser fluids sink, creating a convection current. An example of this is the heating of air near a warm surface, which causes the air to rise and create a circulation pattern.
However, neither conduction nor convection play a significant role in the transfer of energy from the sun to Earth. This is because space is essentially a vacuum, devoid of matter to conduct heat, and there is no air or fluid present for convection to occur.
Instead, energy from the sun reaches Earth primarily through radiation. Radiation is the transfer of energy in the form of electromagnetic waves. In the case of solar energy, it is in the form of light and other electromagnetic radiation emitted by the sun.
These electromagnetic waves travel through the vacuum of space and reach Earth without the need for a material medium or direct contact. This means that energy from the sun can reach Earth through radiation even though there is no air or matter present in space.
In conclusion, energy from the sun reaches Earth primarily through radiation, making option B) radiation only the correct answer.