Answer:

Explanation:
As we know that if the block will complete the circular motion of the path then the speed at the bottom most part of the path must be equal to

now we know that
velocity at the bottom of the path is due to conversion of potential energy to kinetic energy
so we can say it is given as


now we have


Answer:
The correct answer is : a special type of experimental design where subject divides in two groups according their treatment setting.
Explanation:
A two group is a experimental design two groups are the two different groups of subjects divided by the researcher for comparing the data and result to establish relation in variables.
In normal case, one of the two groups one is a group of subjects who get treatment known as experiment or treatment group while other group is known as control group without treatment.
Thus, the correct answer is : a special type of experimental design where subject divides in two groups according their treatment setting.
Physical: the raft needs to float, which means what you make the raft out of must be less dense than water.
The raft would need sturdiness- if the raft is frail, the water might break it
Chemical: It can not react with water and it can not be made of a completely soluable substance (something that would dissolve in it like salt)
Under normal lighting conditions, most diamonds appear to be colorless the naked eye. Many consumers think that all diamonds are colorless, however, in reality, they come in a wide range of colors. Actualcolor differences are very subtle.