Explanation :
Absorption coefficient of a material determines how much sound is absorbed by the material.
To build a soundproof room, Heavy curtains and carpet can be used. They reduce reverberation.
Reverberation means an echoing sound which persists for some time. For example, when we bang on a huge piece of metal, we hear the reverberation even after we stop banging.
Hence, option (A) and (D) are correct.
The final velocity of skater 1 is 3.7 m/s to the right. The right option is O A. 3.7 m/s to the right.
<h3>What is velocity?</h3>
Velocity can be defined as the ratio of the displacement and time of a body.
To calculate the final velocity of Skater 1 we use the formula below.
Formula:
- mu+MU = mv+MV............ Equation 1
Where:
- m = mass of the first skater
- M = mass of the second skater
- u = initial velocity of the first skater
- U = initial velocity of the second skater
- v = final velocity of the first skater
- V = final velocity of the second skater.
make v the subject of the equation.
- v = (mu+MU-MV)/m................ Equation 2
Note: Let left direction represent negative and right direction represent positive.
From the question,
Given:
- m = 105 kg
- u = -2 m/s
- M = 71 kg
- U = 5 m/s
- V = -3.4 m/s.
Substitute these values into equation 2
- v = [(105×(-2))+(71×5)-(71×(-3.4))]/105
- v = (-210+355+241.4)/105
- v = 386.4/105
- v = 3.68 m/s
- v ≈ 3.7 m/s
Hence, the final velocity of skater 1 is 3.7 m/s to the right. The right option is O A. 3.7 m/s to the right.
Learn more about velocity here: brainly.com/question/25749514
Answer: Mechanical waves
Explanation:
Mechanical waves require a medium in order to transport their energy from one location to another. A sound wave is an example of a mechanical wave. Sound waves are incapable of traveling through a vacuum.
Answer:
2.572 m/s²
Explanation:
Convert the given initial velocity and final velocity rates to m/s:
- 65 km/h → 18.0556 m/s
- 35 km/h → 9.72222 m/s
The motorboat's displacement is 45 m during this time.
We are trying to find the acceleration of the boat.
We have the variables v₀, v, a, and Δx. Find the constant acceleration equation that contains all four of these variables.
Substitute the known values into the equation.
- (9.72222)² = (18.0556)² + 2a(45)
- 94.52156173 = 326.0046914 + 90a
- -231.4831296 = 90a
- a = -2.572
The magnitude of the boat's acceleration is |-2.572| = 2.572 m/s².
A good way for me to remember things is to study it, and to write it down! Say you want the formula for speed, I would write the formula multiple times on a piece of paper!
Here's a video that I haven't actually watched, I just looked it up! It might help you out though: <span>https://www.youtube.com/watch?v=-Wqrw4G79Kc</span>
