As they evolved and adapted, those of the fittest survived to reproduce. Those that did not adapt, died.
You need to clean and sand wood of any ruff edges
The formula for<span> </span>mechanical advantage<span> (MA) for levers: You can use the ratio of the input arm length to the output arm length (input/output): Most of the time, levers are used to multiply force to lift heavy objects.</span>
Periscope is a tube containing mirrors or prisms for seeing things which are otherwise not possible to see due to some obstacle. Two mirrors are aligned at 45 degrees through which light bounces off and enables the observer to see beyond the obstacle. This is specially used in submarines.
A kaleidoscope is an optical device which contains mirrors and colored glass pieces in a tube. When the tube is rotated, beautiful patterns are formed due to multiple reflections.
It's true
work measure by joule.
Energy = work/time
= joule/s .
and joule/s represents watt