Answer:

Explanation:
Given data:
Mass of the man, 
Total mechanical energy, 
Height, 
Suppose there is no external force acting on the man. In this situation, the total mechanical energy (kinetic + potential) will remain steady.
Let the speed of the man at 2.6 m be <em>v</em>.
Thus,




Answer:
Explanation:
The heat source for rock formation
Primordial heat: Some heat accumulated during the earth's formation and it is still available to drive the internal heat Engine of the earth. Some of these heat are used to melt rocks and produce magma.
Radioactive sources: Radioactive elements within the earth also serves as heat source for rock formation. Their spontaneous decay produce heat which are sufficient enough to generate enough thermal energy to melt and produce rocks.
This question is a bit ambiguous because all parts of a scientific argument must be supported by valid data. However, among the choices, the closest synonym to "valid data" would be evidence. Evidence is the body of facts or information that support a given idea.
1-Without gravity you can't grow any plant or tree because dirt would fly away
2-We are using gravity for a lot of physics system too
3-All the water on Earth would have been flying in the space
4-There wouldn't be atmosphere.