Answer:
The intensity level of the sound wave due to the ambulance is 153.5 dB.
Explanation:
The intensity level of the sound wave due to the ambulance can be calculated using the following equation:

<u>Where</u>:
I: is the intensity of the sound wave from a siren = 111.2 W/m²
I₀: is the reference intensity = 1.0x10⁻¹² W/m²
Now, since the second sound wave from a nearby ambulance has an intensity level 13 dB we have:

Therefore, the intensity level of the sound wave due to the ambulance is 153.5 dB.
I hope it helps you!
Answer:
Astronauts who are orbiting the Earth often experience sensations of weightlessness. These sensations experienced by orbiting astronauts are the same sensations experienced by anyone who has been temporarily suspended above the seat on an amusement park ride. Not only are the sensations the same (for astronauts and roller coaster riders), but the causes of those sensations of weightlessness are also the same. Unfortunately however, many people have difficulty understanding the causes of weightlessness.
Answer:
<h3>0.69</h3>
Explanation:
Using the Newtons law of motion;

Fm is the moving force = 400N
Ff is the frictional force = μR
μ is the coefficient of kinetic friction
R is the reaction = mg
m is the mass
a is the acceleration
The equation becomes;

Hence the coefficient of kinetic friction between the box and floor is 0.69
Answer:
20kg
Explanation:
heat lost by copper=heat gained by watter
The cyclist is moving by uniformly accelerated motion, with an initial velocity of

and an acceleration of

.
The acceleration is given by

where

is the final velocity and

is the time between the end and the beginning of the motion, and in our case it is 1.75 s. Therefore, from this relationship we can find the final velocity: