Answer:
Explanation:
Let the intensity of the noise be represented by I
Given that
40dB = 10 log 10 ( I /I•) ........ 1
I• is the lowest or threshold intensity of sound made.
I represents the intensity of the sound/ noise
The intensity of noise of 1000flies will be
β = 10 log 10 (1000I/I•)
Open up the bracket
β = 10 log 10(1000)+ 10 log 10(I/I•)
10 log 10(10^3)+10 log 10(I/I•)
3×10(10 log 10) +10 log 10(I/I•)
Recall, 10 log 10 = 1
30×1 + 10 log 10(I/I•).........2
Put equation 1 into 2
β =30+40
= 70db
Answer:
<em>Correct choice: b 4H</em>
Explanation:
<u>Conservation of the mechanical energy</u>
The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):
E = U + K
The GPE is calculated as:
U = mgh
And the kinetic energy is:
Where:
m = mass of the object
g = gravitational acceleration
h = height of the object
v = speed at which the object moves
When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:
When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:
Since the energy is conserved, U1=U2
![\displaystyle mgH=\frac{1}{2}mv^2 \qquad\qquad [1]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2%20%20%20%20%5Cqquad%5Cqquad%20%5B1%5D)
For the speed to be double, we need to drop the snowball from a height H', and:
Operating:
![\displaystyle mgH'=4\frac{1}{2}m(v)^2 \qquad\qquad [2]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%27%3D4%5Cfrac%7B1%7D%7B2%7Dm%28v%29%5E2%20%5Cqquad%5Cqquad%20%5B2%5D)
Dividing [2] by [1]
Simplifying:
Thus:
H' = 4H
Correct choice: b 4H
The answer is A. Force is equal to mass x acceleration. The acceleration due to gravity is a constant so multiplying the mass by 2 would double the force.
We know that a wave is a disturbance that transfers energy through matter or space There are two main types of waves: Mechanical and Electromagnetic. Water waves are mechanical. A mechanical wave is an oscillation of matter to transfers energy, but you always need a medium (substance such as: solid, liquid, gas, plasma) to transport it. The medium for water waves is, in fact, the water. For example, ripple in water is a surface wave. On the other hand, electromagnetic waves don't need a medium to transport, they can do it through the empty space. Then, this is the major characteristic that makes these two types of waves different.
Based on Newton's Law, the event is not fair because:
<span>No, because a basketball is bigger than a baseball, and objects that are bigger accelerate slower.
I hope my answer has come to your help. God bless and have a nice day ahead!</span>
