Answer:
The heat transferred from water to skin is 6913.5 J.
Explanation:
Given that,
Weight of water = 25.0 g
Suppose that water and steam, initially at 100°C, are cooled down to skin temperature, 34°C, when they come in contact with your skin. Assume that the steam condenses extremely fast. We will further assume a constant specific heat capacity c=4190 J/(kg°K) for both liquid water and steam.
We need to calculate the heat transferred from water to skin
Using formula for stream
Put the value into the formula
Hence, The heat transferred from water to skin is 6913.5 J.
Answer:
<em>The object could fall from six times the original height and still be safe</em>
Explanation:
<u>Free Falling</u>
When an object is released from rest in free air (no friction), the motion is completely dependant on the acceleration of gravity g.
If we drop an object of mass m near the Earth surface from a height h, it has initial mechanical energy of
When the object strikes the ground, all the mechanical energy (only potential energy) becomes into kinetic energy
Where v is the speed just before hitting the ground
If we know the speed v is safe for the integrity of the object, then we can know the height it was dropped from
Solving for h
If the drop had occurred in the Moon, then
Where hM, vM and gM are the corresponding parameters on the Moon. We know v is the safe hitting speed and the gravitational acceleration on the Moon is g_M=1/6 g
This means the object could fall from six times the original height and still be safe
I will discuss what is a gravitational force since no figures are attached or given. An objects weight is dependent upon its location in the universe
because they exhibit gravitational waves. For example, the earth is a massive
planet. Because of its massiveness, it exhibits a strong gravitational force
within it. In turn, the objects near the earth will be attracted to it and
thereby feels a much stronger gravity on earth. That is why bodies of water,
despite its liquid features, stick to the earth. The heavier the body is, the
stronger its gravitational pull. Another example is the Milky Way Galaxy, there is a
gravitational pull because it is to other galaxies. Also, other galaxies are
heavier than the earth and therefore, it is attracted to the Milky Way galaxy
because of its gravitational pull.
Answer:
The value of total energy needed per minute for the humidifier = 77.78 KJ
Explanation:
Total energy per minute the humidifier required = Energy required to heat water to boiling point) + Energy required to convert liquid water into vapor at the boiling point) ----- (1)
Specific heat of water = 4190 
The heat of vaporization is = 2256 
Mass = 0.030 kg
Energy needed to heat water to boiling point = 
Energy needed to heat water to boiling point = 0.030 × 4.19 × (100 - 20)
Energy (
) = 10.08 KJ
Energy needed to convert liquid water into vapor at the boiling point
= 0.030 × 2256 = 67.68 KJ
Thus the total energy needed E = +
E = 10.08 + 67.68
E = 77.78 KJ
This is the value of total energy needed per minute for the humidifier.
