Ultraviolet light. It can cause skin cancer and that is why we wear sunscreen. We also wear sunglasses because some research has shown that it can damage eyes. Although it can be dangerous, it can also kill certain bacterias.
The reason why the snails are dead because the snails lack oxygen for it is a model of closed ecosystem. Another reason to this is that they lack abiotic factors that they need in surviving or as they live for the place that they are living lacks a lot and are not enough for them to last or survive. Lastly, the water could have not been a contributor for them to live for they may not be able to live in a water environment and could only dwell in land.
Principle: Pythagorean theorem
Given:
Let a = boat velocity = 25 miles per hour
b = river velocity = 10 miles per hour
Required: c = actual velocity
Solution:
c^2 = a^2 + b^2
c^2 = (25)^2 + (10)^2
c^2 = 725
(c^2)^0.5 = (725)^0.5
c = 26.93 miles per hour
<em>ANSWER: Actual boat velocity is 26.93 miles per hour</em>
Metals are good conductors because the molecules that are inside the metal are tightly packed together. This is why the heat moves through the metal quickly.