Answer:
Before giving an injection, a nurse dabs some alcohol onto the patient`s arm. This makes the patient`s skin feels cold. Explain Why ?
<em> Evaporative cooling makes this to be possible</em>
Explanation:
The concept
For a liquid to evaporate, there must be a breakdown of the bond between the molecules of the liquid. These bonds are broken when the molecules gain heat energy. So basically evaporation occurs when the molecules of the substance gain energy in form of heat.
Our Scenario
Just like the way our body excretes sweat on a sunny day, alcohol takes energy from the skin to evaporate. The bond holding the molecules of alcohol breaks faster due to its low boiling point and this account why it evaporates faster. The sudden evaporation of alcohol when dabbed on the skin results in quick utilization of heat energy making the skin feel cold for some time.
The utilization of heat energy from the skin results in evaporation cooling which makes the skin feel colder.
I believe one of these are called Elliptical, Spiral, and Irregular Galaxies.
600
mph
Velocity is the distance traveled in a given time, or
v
=
x
t
where
v
is velocity,
x
is distance and
t
is time.
Here,
x
=
3000
and
t
=
5.0
, so
v
=
x
t
=
3000
5
=
600
Don't forget units. Since the question's data is in miles and hours, the units will be miles per hour, or mph, so
3000
miles
5
hours
=
600
miles
hour
=
600
mph
Answer:
C. 9.9 cm
Explanation:
The location of the object, u = 14 cm
The location of the image, v = 5.8 cm
The focal length of the mirror, f = Required
The mirror formula for a convex mirror is given as follows;
Therefore, we get;
Therefore;
The focal length of the mirror, f ≈ 9.9 cm
