Answer:
v_average = 15 m / s
Explanation:
The average speed can be found in two ways,
* taking the distance traveled and divide it by the time spent
* taking the velocities in each time interval and then finding the weighted average by the time fraction
v_average = 1 / t_total ∑ 
vi ti
Let's apply this last equation
Total time is
t = t₁ + t₂
t = 10 + 10 = 20 min
v_average = 10/20 10 + 10/20 20
v_average = 10/2 + 20/2
v_average = 15 m / s
Answer:
c glass
Explanation:
beacause glass is transparent and it would be easier to for refraction
Answer:
the image is virtual and erect and the lens divergent; therefore the correct answer is C
Explanation:
In a thin lens the magnification given by
m = h '/ h = - q / p
where h ’is the height of the image, h is the height of the object, q is the distance to the image and p is the distance to the object.
It indicates that the object is straight and is placed at a distance p> f
analyze the situation tells us that the magnification is positive so the distance to the image must be negative, that is, that the image is on the same side as the object.
Consequently the lens must be divergent
The magnification value is
0.4 = h ’/ h
h ’= 0.4 h
therefore the erect images
therefore the image is virtual and erect and the lens divergent; therefore the correct answer is C
Answer:
When fuels burn in combustion reactions, they release useful thermal energy (heat). Combustion reactions are used to heat our homes, power most cars, and to generate a lot of our electricity.
Energy production from the reaction is what drives life and human greed. We stay alive by eating carbon-rich compounds, which are then burned in a spectacularly controlled and efficient manner to provide us with energy. It is the all-important energy term in the combustion equation that has made life on Earth possible
Answer:
C. cools adiabatically as it sinks to a lower elevation
Explanation:
Condensation is the phenomenon where there is a change of the state of matter from gas phase to liquid phase. Vaporization is the reverse of condensation. If a process occurs without the transfer of heat and mass of a thermodynamic system with its surroundings then it is known as an adiabatic process.
Moist air consists of water in gaseous state, so when it is cooled without any exchange of mass or heat there is change of phase.
