The intensity ,i from a point source decreases with the inverse square of the distance, r from the source. suppose that you are listening to your favourite music coming away from a speaker(regarded as a point source and in an open area) placed exactly r1 from you. then you suddenly decide to move away to a new position ,r2 which is exactly twice as far away from the speaker.
calculate by how many decibels ,db does the sound intensity level ,β drop ,when you move twice as far away from the speaker to your new position.

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?