C. Answer the following question briefly but subtantially
1 How are EM waves different from mechanical waves?
2 Give two source of EM waves in the Earth s environment.
Answer (1)
1. Electromagnetic waves, or EM waves in short, can travel through a vacuum or empty space. Meanwhile, mechanical waves need a medium to travel. 2. Sun - The sun releases Ultraviolet (UV) rays into the Earth’s environment. This UV rays can be utilized by our body to make Vitamin D. But too much exposure to it can cause skin cancer and other skin related conditions. Ionosphere - This is a layer in the Earth’s atmosphere. Atoms / gases in this layer usually goes to an excited state from solar radition. This helps make EM waves suxh as infrared travel. It also consists of many different EM waves, ranging from very short to very long.
