Answer:
The answer is convection.
Explanation:
There are three types of heat transfer: conduction, convection and radiation.
- Conduction occurs when two objects touch each other and transfer heat.
- Convection occurs when an object heats its surrounding fluid (like air, or water) and, since the hot fluids are less dense than the cold ones, they go up. So convection is a type of heat transfer that usually goes from down to up.
- Radiation occurs when objects emanate heat in the form of electromagnetic waves that propagates in all directions.
So in this case, when the marshmallow is above the fire, it is exposed to convection, which does not occur when it is on the side of the fire.
Answer:
the mass of water is 0.3 Kg
Explanation:
since the container is well-insulated, the heat released by the copper is absorbed by the water , therefore:
Q water + Q copper = Q surroundings =0 (insulated)
Q water = - Q copper
since Q = m * c * ( T eq - Ti ) , where m = mass, c = specific heat, T eq = equilibrium temperature and Ti = initial temperature
and denoting w as water and co as copper :
m w * c w * (T eq - Tiw) = - m co * c co * (T eq - Ti co) = m co * c co * (T co - Ti eq)
m w = m co * c co * (T co - Ti eq) / [ c w * (T eq - Tiw) ]
We take the specific heat of water as c= 1 cal/g °C = 4.186 J/g °C . Also the specific heat of copper can be found in tables → at 25°C c co = 0.385 J/g°C
if we assume that both specific heats do not change during the process (or the change is insignificant)
m w = m co * c co * (T eq - Ti co) / [ c w * (T eq - Tiw) ]
m w= 1.80 kg * 0.385 J/g°C ( 150°C - 70°C) /( 4.186 J/g°C ( 70°C- 27°C))
m w= 0.3 kg
Answer:
a) It reduces the kinetic energy loss of the stunt person.
"in the paper making process, the pulp is strained to create the initial textured/brittle paper, but the process doesn't end there. The textured paper must be put through high pressured steam rollers to create the smooth paper you've come to know. This setting process causes all the fibers to be pressed flat and packed together evenly on the surface. When paper gets wet, it "unsets" itself, breaking up the tension that held the fibers together, again causing the uneven texture it initially had." Got this from reddit
