Answer:
Explanation:
101 dB = 10.1 B.
Maximum intensity of sound allowed = 10.1 B
Intensity of sound in terms of W/m² can be found as follows
log (I / I₀) = 10.1
I / I₀ = 10¹⁰°¹
I = I₀ X 10¹⁰°¹
= 10⁻¹² X 10¹⁰°¹
= 10⁻¹°⁹ W/m²
105 m above the ground the this intensity will be 105² times
intensity at source point = 10⁻¹°⁹ x 105²
= 138.79 W/m²
energy of sound from source
= 4π times
= 4 x 3.14 x 138.79
= 1743.28W/m²
To calculate in terms of decibel :
log 1743.28 / 10⁻¹²
= log 1743.28 +12
= 15.24 B
= 152.4 dB .
152.4 dB .
Answer:
The correct option is 'd': The change in shape of an object.
Explanation:
Since by definition physical change is defined as a change that changes only the form of an object or substance and producing no change in the chemical composition of the substance. Physical changes are reversible in nature.
As we can see from all the options the change in the shape of the object is a reversible change as we can always remold any substance in any shape, thus it confirms to a physical change.
The change in the molecular composition of an object is a hallmark of a chemical reaction thus indicates a chemical change.
The smell change in an object is an indication of a chemical change in the object hence is not a physical change.
Answer: Water is the world's most common acid and base.
Question:
If you push a bowling ball and a golf ball with an equal force what will happen
Answer:
B)
Explanation:
Larger than the force used to push the object that has less mass. A golf ball and a bowling ball are moving at the same velocity. When gravity and air resistance are equal, the object has drawn its terminal velocity.
Answer
4
Explanation:
four rays can also explain the ray diagram if the object is at infinity
