Answer:
An apple hanging at a branch has potential energy due its position. It can be written as PE= mgh where m is the mass of the apple h is the distance between the apple and the ground and g is the acceleration due to gravity.
as the apple falls from the tree it loses its potential energy and gains kinetic energy due to the movement of the apple. Its kinetic energy will be given by KE= 1/2mv² where m is the mass of the apple and v is the speed with which the apple falls.
As the apple falls the height or the distance reduces and PE becomes reduces. But it gains Kinetic energy due to its speed.
But when the apple falls to the ground and comes to rest its kinetic energy is converted to potential energy.
thus the total energy remains the same. it changes from one form to the other but remains unaltered.
Answer:
solution:
dT/dx =T2-T1/L
&
q_x = -k*(dT/dx)
<u>Case (1) </u>
dT/dx= (-20-50)/0.35==> -280 K/m
q_x =-50*(-280)*10^3==>14 kW
Case (2)
dT/dx= (-10+30)/0.35==> 80 K/m
q_x =-50*(80)*10^3==>-4 kW
Case (2)
dT/dx= (-10+30)/0.35==> 80 K/m
q_x =-50*(80)*10^3==>-4 kW
Case (3)
q_x =-50*(160)*10^3==>-8 kW
T2=T1+dT/dx*L=70+160*0.25==> 110° C
Case (4)
q_x =-50*(-80)*10^3==>4 kW
T1=T2-dT/dx*L=40+80*0.25==> 60° C
Case (5)
q_x =-50*(200)*10^3==>-10 kW
T1=T2-dT/dx*L=30-200*0.25==> -20° C
note:
all graph are attached
there are 3 atoms in each silver sulfide
Answer:
Metals are the good conductors of heat while plastic is a non metal and is not good in conductivity.
Explanation:
From the molecular point of view we usually define conductivity in terms of free electrons which are in abundance in metal and electrons do transfer heat. So when you touch a piece of metal these free electron of metal take that heat from your hand and transfer to the cooler part. "Flow of heat from hotter to colder part". That is the reason it feels colder upon touching the piece of metal. However Plastics do not have this characteristic of conduction of heat.
