Answer:
v = 70 m/s
Explanation:
Range on the cannon ball is given as

here the angle of the projection of the ball is given as 45 degree
now we know that if the velocity of the ball is "v" then its two components will be given as


so here time of flight of the motion is given as


also the range is given as


now plug in all data in this equation


 
        
             
        
        
        
Answer:
So the sound intensity level they would experience without the earplugs is 110.32dB.
Explanation:
Given data
Sound intensity by factor =215
Sound intensity level =87 dB
To find
Sound intensity level they would experience without the earplugs
Solution
First we need to find the new sound intensity level 
So

The dB can be calculated as:

Substitute the given values

So the sound intensity level they would experience without the earplugs is 110.32dB.