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.
By measuring the Galvanic skin response, Dr. Laub is trying to avoid the problem of:
<h3>What are demand characteristics?</h3>
Demand characteristics are a form of behavior that participants in a research work exhibit. If they are able to fathom the cues in the research, they often tend to change the way that they behave.
If they change the way they behave, accurate results will not be obtained. So, this issue must be avoided at all costs and that is why Dr. Laub measures the Galvanic skin response.
Learn more about demand characteristics here:
brainly.com/question/17188674
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