Answer:
random assignment
Explanation:
Random assignment is an experimental technique that seeks to form random and fully randomized experimental groups in relation to the treatments presented in the research. This type of technique prevents the formation of "combined groups" that show the differences to each other and can generate a comprehensive result on the research, thus the random formation of diverse groups that can represent a much larger and different population.
An example of this can be seen in the question above, where the researcher decides the formation of the group that will receive the medicine and the group that will receive the placebo, completely randomly.
Answer: Alfonso thinking his father would likely call him a sissy
This is because the conflict is him having to choose one or another. Either get a cool haircut, or get the haircut and be scolded by his father.
Answer:
The collision occurs at a height of 1/3 of the total height of cliff.
Explanation:
The situation is represented in the attached figure:
For the stone dropped from top of cliff we have
Initial velocity of drop= 0 m/s.
Now the time at which it attains a velocity of 2v is obtained from first equation of kinematics as

Thus the distance it covers in this time can be calculated using third equation of kinematics as

For the stone thrown upwards the velocity at collision is give as 'v' thus the velocity at which it is thrown upwards can be calculated by first equation of kinematics as

The height over which it changes it's velocity from '3v' to 'v' can be again obtained from third equation of kinematics as


Thus the collision occurs at at a fraction of 1/3 of height.