Extensional stress. is your answer.
Answer:
Since strong nuclear forces involve only nuclear particles (not electrons, bonds, etc) items 3 and 4 are eliminated.
Again item 2 refers to bonds between atoms and is eliminated.
This leaves only item 1.
Nuclear forces are very short range forces between components of the nucleus.
Weak nuclear forces are trillions of times smaller than strong forces.
Gravitational forces are much much smaller than the weak nuclear force.
I believe that a light bulb releases visible light and a radio antenna releases a radio waves
Answer
Maximum speed at 75 m radius will be 22.625 m /sec
Explanation:
We have given radius of the curve r = 150 m
Maximum speed 
Coefficient of friction 
Now new radius r = 75 m
So maximum speed at new radius 