Answer:
The Moon revolves around the Earth and rotates on its axis with the same period. • The combined effect of these two motions means that one side of the Moon always faces the Earth.
The skydiver has a bunch of gravitational potential energy. The best example of chemical potential energy is gasoline.
A solar eclipse occurs when the moon crosses in front of the Sun, blocking some or all of its rays. A lunar eclipse happens when the moon is directly behind the earth, blocking the moon from receiving light. The only light comes from the light on earth's reflected shadow.
You can look at a lunar eclipse because there is very little light or none at all. You can't look at a solar eclipse because you are looking directly at the sun unless it is complete. Before totality, only some of the Sun is blocked, causing your pupils dilate to let in more light. Since they do this, more of the Sun's rays can be let in to the eye, which effectively allows your eyes to burn.
Some doctors and eye care specialists say that after someone complains of blindness after looking at a solar eclipse unaided, they can see what the Sun and moon looked like at the time that they looked at it, as it is burned onto their retinas.
Answer:
The true weight of the aluminium is 
4.5021 kg
Explanation:
Given data
= 4.5 kg
= 1.29 
= 2.7× 
The true mass of the aluminium is given by
Put all the values in above equation we get
4.5021 kg
Therefore the true weight of the aluminium is 4.5021 kg
Answer:
#see solution for details
Explanation:
-Uncertainty refers to an estimate of the amount by which a result may differ from this value,
-Precision refers to how closely repeated measurements agree with each other.
-Accuracy refers to how closely a measured value agrees with the correct value.
-The number of significant figures is the number of digits believed to be correct by the person doing the measuring. Therefore, choosing the correct number of significant figures reduces the deviation from the point of accuracy/uncertainty or precision and thereby reducing margin of error in the ensuing calculations.
