Explanation:
The efficiency of a machine is 70% means 30% of the applied force is wasted in overcoming friction and 70% of the applied force is used to do the work
The hot gases produce their own characteristic pattern of spectral lines, which remain fixed as the temperature increases moderately.
<h3><u>Explanation: </u></h3>
A continuous light spectrum emitted by excited atoms of a hot gas with dark spaces in between due to scattered light of specific wavelengths is termed as an atomic spectrum. A hot gas has excited electrons and produces an emission spectrum; the scattered light forming dark bands are called spectral lines.
Fraunhofer closely observed sunlight by expanding the spectrum and a huge number of dark spectral lines were seen. "Robert Bunsen and Gustav Kirchhoff" discovered that when certain chemicals were burnt using a Bunsen burner, atomic spectra with spectral lines were seen. Atomic spectral pattern is thus a unique characteristic of any gas and can be used to independently identify presence of elements.
The spectrum change does not depend greatly on increasing temperatures and hence no significant change is observed in the emitted spectrum with moderate increase in temperature.
The total power emitted by an object via radiation is:
where:
A is the surface of the object (in our problem,
is the emissivity of the object (in our problem,
)
is the Stefan-Boltzmann constant
T is the absolute temperature of the object, which in our case is
Substituting these values, we find the power emitted by radiation:
So, the correct answer is D.
In this question all required information's are already provided. Based on these details the answer to the question can be easily determined. Let us now write down all the information's that are already given.
Mass of the roller coaster = 1000 kg
Velocity of the roller coaster = 20.0 m/s
We know the formula for finding the kinetic energy is
Kinetic energy = 0.5 * mass * (velocity) ^2
= 0.5 * 1000 * (20)^2
= 0.5 * 1000 * 400
= 200000 Joules
So the Kinetic energy of the roller coaster is 200000 joules.
i hope this helps you friend good luck on your quiz or lesson
I thinks its period because they are on the last column to the right
