Answer:
The value is 
Explanation:
From the question we are told that
The mass of matter converted to energy on first test is 
The mass of matter converted to energy on second test 
Generally the amount of energy that was released by the explosion is mathematically represented as

=> ![E = 1.5 *10^{-3} * [ 3.0 *10^{8}]^2](https://tex.z-dn.net/?f=E%20%3D%20%201.5%20%2A10%5E%7B-3%7D%20%20%2A%20%5B%203.0%20%2A10%5E%7B8%7D%5D%5E2)
=> 
Answer: 0.5 m
Explanation:
Given
Mass of the person is 
Trampoline launches the person into the air up to height of 
Force experience by springs is 
Here, the work done on displacing the springs is equivalent to the Potential energy acquired by the person i.e.
![\Rightarrow F\cdot x=mgh\quad [\text{x=displacement of the trampoline}]\\\\\text{Insert the values}\\\\\Rightarrow x=\dfrac{50\times 9.8\times 2}{1960}\\\\\Rightarrow x=\dfrac{980}{1960}\\\\\Rightarrow x=0.5\ m](https://tex.z-dn.net/?f=%5CRightarrow%20F%5Ccdot%20x%3Dmgh%5Cquad%20%5B%5Ctext%7Bx%3Ddisplacement%20of%20the%20trampoline%7D%5D%5C%5C%5C%5C%5Ctext%7BInsert%20the%20values%7D%5C%5C%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B50%5Ctimes%209.8%5Ctimes%202%7D%7B1960%7D%5C%5C%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B980%7D%7B1960%7D%5C%5C%5C%5C%5CRightarrow%20x%3D0.5%5C%20m)
120 minutes=2 hours
20/2= 10mph