Power = Work/time
Work= energy
Potential energy =mxgxh
Power=mxgxh/t
Power=68x10x7/9
Power=529 watts
Genetically engineering endangered keystone species that are vital to the environment to be more resilient against harmful predators and/or toxins, pathogens, etc.
The answer is B. Gases and particles in earth’s atmosphere scatter sunlight in all directions
Answer:
(a) 
(b) 
Explanation:
Given data
Distance r₁=50 m
Distance r₂=2 m
Intensity I₂=2.0 W/m²
To find
(a) The Sound Intensity I₁
(b) The Sound Intensity level β
Solution
For (a) the Sound Intensity I₁

For (b) the Sound Intensity level β
The Sound Intensity level β is calculated as follow
