Answer:
Sample Response: In a vacuum, there are no atoms or particles that interfere with the path of light. However, in other media, the speed of light is lower than 3.0 × 108 m/s because the wave is continuously absorbed and re-emitted by each atom in its path. The differences in speed are due to the composition of the medium and the density of the particles in the medium.
Explanation:
Answer:
The speed of sound is affected by temperature and humidity. Because it is less dense, sound passes through hot air faster than it passes through cold air. ... The attenuation of sound in air is affected by the relative humidity. Dry air absorbs far more acoustical energy than does moist air.
Answer: 500 Watts
Explanation:
Power 
is the speed with which work 
is done. Its unit is Watts (), being 
.
Power is mathematically expressed as:
(1)
Where 
is the time during which work is performed.
On the other hand, the Work done by a Force 
refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path. It is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy). Therefore, 1 Joule is the work done by a force of 1 Newton when moving an object, in the direction of the force, along 1 meter (
).
When the applied force is constant and the direction of the force and the direction of the movement are parallel, the equation to calculate it is:
(2)
In this case, we have the following data:
So, let's calculate the work done by Peter and then find how much power is involved:
From (2):
(3)
(4)
Substituting (4) in (1):
(5)
Finally:
I believe this question ask for the energy dissipated by
friction.
The overall energy equation for this is:
F = PE – KE
where F is friction loss, PE is potential energy = m g h,
KE is kinetic energy = 0.5 m v^2
<span>F = 66 kg * 9.8 m/s^2 * 170 m – 0.5 * 66 kg * (11 m/s)^2</span>
<span>F = 105,963 J ~ 106,000 J </span>
