The scientist who discovered the two elements radium and polonium would be Marie Curie in 1898.
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Answer: Energy can neither be created nor destroyed, rather it is converted from one form to another
Explanation:
The principle of conversation of energy explains how energy is conserved in nature by being converted from one form to another such that no energy is created nor destroyed.
Practical examples include:
- electrical pressing iron that converts electrical energy to heat energy
- solar panels that converts solar energy to electrical energy
- Car batteries that converts chemical energy to light energy etc
Heat absorbed by the solar collector = Area*Irradiance = 5.3*995 = 5273.5 W
Heat Q in joules absorbed in t hours = Heat used to heat water. That is,
5273.5*t = mCΔT; where mass = volume*density = 1*1000 = 1000 kg
Therefore;
5273.5t = 1000*4186*(65-20) = 188370000
t = 188370000/5273.5 = 35720.11 seconds = 35720.11/(60*60) hours ≈ 9.92 hours.
It will take approximately 9.92 hours.
Answer:
Lubrication is used to reduce friction. It is generally used for moving machine parts. The lubricants are the substances which are used to reduce the friction which acts between two surfaces in contact, between which relative motion can occur.
