Answer:
Typically found in eukaryotic cells, centrioles are cylindrical (tube-like) structures/organelles composed of microtubules. In the cell, centrioles aid in cell division by facilitating the separation of chromosomes. For this reason, they are located near the nucleus.
Work = force * distance.
We must produce twice as much energy as we are lifting the weight twice as high.
But we are not increasing the force so we must increase the length of the ramp ( distance ) instead.
The new length will be twice as great as the previous length.
So 8 metres is required.
25 kg * 8 m = work = 100 kg * 2 m
Answer:
Tension in the string is equal to 58.33 N ( this will be the strength of the string )
Explanation:
We have given mass m = 1.7 kg
radius of the circle r = 0.48 m
Kinetic energy is given 14 J
Kinetic energy is equal to 
So 

v = 4.05 m/sec
Centripetal force is equal to 
So tension in the string will be equal to 58.33 N ( this will be the strength of the string )
The physical changes are you are breaking down the food u eat and the chemical changes are when the enzymes in your stomach break down the food that you have already eaten