Answer:
Explanation:
When a body is held against a vertical wall , to keep them in balanced position , normal force is applied on their surface . this force creates normal reaction which acts against the normal force and it is equal to the normal force as per newton's third law . Ultimately friction force is created which is proportional to normal force and it acts in vertically upward direction . It prevents the body from falling down .
Hence normal force = reaction force .
From second law also net force is zero , so if normal force is N and reaction force is R
R - N = mass x acceleration = mass x 0 = 0
R = N .
Ranking normal force from highest to smallest
150 N , 130 N , 120 N
B )
Frictional force is equal to the weight of the body because the body is held at rest .
Ranking of frictional force form largest to smallest
7 kg , 5 kg , 3 kg , 1 kg .
Here frictional force is irrespective of the normal force acting on the body because frictional force adjusts itself so that it becomes equal to weight in all cases here because it always balances the weight of the body .
Trees. Every time the wind blows there is a wave of motion which is movement
interesting question.
how much fuel to hover over one place ?
The Foucault pendulum is a v v v long pendulum which can show the eart's rotation over time if the pend bob motion is tracked and recorded
Answer:L=109.16 m
Explanation:
Given
initial temperature 
Final Temperature 
mass flow rate of cold fluid 
Initial Geothermal water temperature 
Let final Temperature be T
mass flow rate of geothermal water 
diameter of inner wall 

specific heat of water 
balancing energy
Heat lost by hot fluid=heat gained by cold Fluid




As heat exchanger is counter flow therefore





heat lost or gain by Fluid is equal to heat transfer in the heat exchanger
(LMTD)



