Mechanical energy E = mgh + 1/2mv²
When he starts, let h = 0 ⇒ E₁ = 1/2mv₁²
When he reaches height h ⇒ E₂ = mgh + 1/2mv₂²
Without friction, energy is conserved at all times.
E₁ = E₂
↓
1/2mv₁² = mgh + 1/2mv₂²
↓
1/2v₁² = gh + 1/2v₂²
↓
gh = 1/2(v₁² - v₂²)
↓
h = (v₁² - v₂²) / (2g)
Answer:
The alternative energy sources are defined as those resources that are used in place of the natural and non-renewable resources. This resources plays an important role in the conservation of natural resources.
The fossil fuels are the resources on which the people are directly dependent. Burning up of these fossils leads to the emission of carbon, which has a direct impact on earth. A small increase in the amount of carbon dioxide can lead to the increase in the surface temperature of earth.
In addition to this, these fossil fuels such as coal, petroleum, oil and natural gases are found to be present in a limited proportion, and it is a very expensive process to obtain these resources, so sustainable development method must be adopted in order to save this natural resources for the future generation.
Some of the examples of alternative resources that are widely used in place of fossil fuels are wind energy, solar energy, tidal energy, biomass energy and bio-fuels.
Thus, it is very important to develop and use alternative resources.
Answer:
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The tilt of the moon's axis does not allow for monthly alignment, so the lunar and solar eclipse do not happen every month.
<h3>How do the lunar and solar eclipse occur?</h3>
- For the occurrence of lunar and solar eclipse, the sun, moon and the earth must remain in a plan and along a straight line.
- When the earth appears in between the sun and the moon, lunar eclipse occurs.
- When the moon appears in between the sun and the earth, solar eclipse occurs.
- The moon and earth are rotating not only around the sun, but also around the black hole of Milky way galaxy.
- So they are not present in a plan as well as in a straight line in every full moon and new moon time.
Thus, we can conclude that the option D is correct.
Learn more about the lunar eclipse and solar eclipse here:
brainly.com/question/8643
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