The linear velocity of a rotating object is the product of the angular velocity and the radius of the circular motion. Angular velocity is the rate of the change of angular displacement of a body that is in a circular motion. It is a vector quantity so it consists of a magnitude and direction. From the problem, the angular velocity is 5.9 rad per second and the radius is given as 12 centimeters. We calculate as follows:
Linear velocity = angular velocity (radius)
Linear velocity = 5.9 (12 ) = 70.8 cm / s
The linear velocity of the body in motion is 70.8 centimeters per second or 0.708 meters per second.
Answer:
Option A
Carrots are cut into small pieces and mixed into a salad
Explanation:
When physical changes occur, the actual composition remain the same but the molecules are re-arranged. Therefore, when carrots are cut into smaller pieces and mixed into salad, there will be no chemical reaction hence the actual composition will remain the same despite being cut and molecules in it re-arranged. Considering the other options, new substances are formed hence they are deemed as chemical changes. Therefore, option A is correct.
Answer: Δβ (dB) = -13.1dB
Explanation:
The intensity of sound is inversely proportional to the square of the distance between them.
I ∝ 1/r²
I₁/I₂= r₂²/r₁² .....1
When the listener increases his distance from the source by a factor of 4.49.
Then,
r₂/r₁= 4.49
From equation 1
I₁/I₂ = (4.49)²
I₁/I₂ = 20.16
I₂/I₁ = 1/20.16
The change in sound intensity in dB can be given as
Δβ (dB) = 10 log(I₂/l₁) = 10log(1/20.6) = -13.1dB
