If a sound is 30 db and its absolute pressure was 66 x 10-9 pa, what must have been the reference pressure?

Given:

I = 30dB

P = 66 × Pa

Solution:

Formula used:

I =           (1)

where,

I = intensity of sound

P = absolute pressure

= reference pressure

Using Eqn (1), we get:

=

= 2.08 × Pa

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft

the ima (higher than 1m) will be greater than the ima with the height of 1m.