Answer:
v=32.9m/s
Explanation:
The acceleration needed to mantain a circular motion of radius r and speed v is given by the equation 
This is the centripetal acceleration. The person will feel what is called a centrifugal acceleration, of the same value, because he is not in an inertial frame (thus subject to fictitious forces, product of inertia).
We want to know the speed of his head when it is subject to 12.5 times the value of the acceleration of gravity while moving on a 8.84m radius circle, so we must do:

Answer:
b. The current stays the same.
Explanation:
In the case given current is supplied by the battery to a bulb . Here, we should know that bulb also apply resistance to the flow of current .
Now, when an identical bulb is connected in parallel to the original bulb .
Therefore, both the resistance( bulb) are in parallel.
We know, when two resistance are in parallel , current through them is same and voltage is divided between them.
Therefore, in this case current stays same in the original bulb.
Hence, this is the required solution.
Answer: It would be 75
Explanation: If your pushing on the floor at a rate of 5 for 15 seconds you would multiply the numbers and get 75
Shear Stress= Force along the tangent/ Area
= 2700/π*r^2
=2700/3.14*16
=54