Answer:
P = 5880 J
Explanation:
Given that,
The mass of the block, m = 30 kg
The block is sitting at a height of 20 m.
The block will have gravitational potential energy. The formula for gravitational potential energy is given by :

So, the required potential energy is equal to 5880 J.
Answer: physical or mechanical weathering
Explanation:
Mechanical weathering which is also referred to as the physical weathering occurs when a rock is broken down into smaller pieces. In this case, there will be a physical change of the rock but its composition will not change.
Some examples include ice freezing and expansion of the cracks in the rock, Smstrong winds that carrycpieces of sand which then sandblast surfaces, moving water which causes abrasion etc.
In a direct current the electric charge flows in one direction.
in an alternating the electric charge changes in its direction periodically.
Answer:
Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly 78% nitrogen and 21% oxygen 0.97% argon and carbon dioxide 0.04% trace amounts of other gases, and water vapor. This mixture of gases is commonly known as air. Explanation: