Answer:
232 J/K
Explanation:
The amount of heat gained by the air = the amount of heat lost by the tea.
q_air = -q_tea
q = -mCΔT
q = -(0.250 kg) (4184 J/kg/ºC) (20.0ºC − 85.0ºC)
q = 68,000 J
The change in entropy is:
dS = dQ/T
Since the room temperature is constant (isothermal):
ΔS = ΔQ/T
Plug in values (remember to use absolute temperature):
ΔS = (68,000 J) / (293 K)
ΔS = 232 J/K
A geologic event causes changes to the physical makeup of a particular place and occurs slowly.
Geological events are what causes numerous changes and phenomena on the Earth's surface. Examples of these events include cliff erosion, volcanic eruption, or sedimentation at a mouth of a river.
Geological processes are extremely slow. However, because of the immense lengths of time involved, huge physical changes do occur - mountains are created and destroyed, continents form, break up and move over the surface of the Earth, coastlines change and rivers and glaciers erode huge valleys.
Geological events are both classified as internal and external. This means that these events occur both in the Earth's surface and interior.
Answer:
b) The star is moving away from us.
Explanation:
If an object moves toward us, the light waves it emits are compressed - the wavelength of the light will be shorter, making the light bluer. On the other hand, if an object moves away from us, the light waves are stretched, making it redder. If from laboratory measurements we know that a specific hydrogen spectral line appears at the wavelength of 121.6 nanometers (nm) and the spectrum of a particular star shows the same hydrogen line appearing at the wavelength of 121.8 nm, we can conclude that the star is moving away from npos, since the wavelength related to that star is more expanded.
Answer:
1.65
Explanation:
The equation of the forces along the horizontal direction is:
(1)
where
F = 65 N is the force applied with the push
is the frictional force
m = 4 kg is the mass
is the acceleration
The force of friction can be written as 
(2), where
is the coefficient of kinetic friction
R is the normal force exerted by the floor
The equation of forces along the vertical direction is
(3)
since the bookcase is in equilibrium. Substituting (2) and (3) into (1), we find
And solving for ,
Answer: 3.33 m/s
Explanation:
Assuming the questions is to convert 12 km/h to meter per second (m/s), let's begin:
In order to make the conversion, we have to know the following:
And:
Keeping this in mind, we can make the conversion:
Then:
