If one firecracker produces a sound intensity of 90db, what would be the intensity of a sound produced by 1000 firecrackers, all going off at once?

90db

Explanation:

The 1000, will produce sa.e intensity, since the firecrackers are made of same materials

additional intensity of 30db result in 120db

Explanation:

Sound intensity is defined as the sound power per unit area in other words, it is the power carried by sound waves per unit area in a direction perpendicular to that area. The common approach to sound intensity measurement is to use the decibel scale to measure the ratio of a given intensity I to the threshold of hearing intensity.

Since log 1000=3

Therefore, 10 log 1000=30 db assuming that the distance is the same in both cases.

result in 120db i.e 90+30 = 120db. Which is painful at that point.

a, c, d, e are all applying about success strategies.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s