Answer:
Step by step explanation:
Friction is the opposition offered to the movement of a surface on another and depends on the nature of the surfaces in contact.
<h3>What is friction?</h3>
The term friction refers to the opposition that is offered by surfaces in contact when they move over each other. The question is incomplete but I will try to help you the much I can.
Now recall that fricton only depends on the nature of the surfaces in contact. The friction is te reason when heat is provides in the moving parts of machines.
Learn more about friction: brainly.com/question/15117038
Explanation:
<u><em>Deviation</em><em> </em><em>:</em><em> </em></u><em> </em>
It means the difference between a expected value of a measurement or an observation vs the actual value.
<em><u>Incidence</u></em><em><u> </u></em><em><u>:</u></em>
A straight line, ray of light, etc.., hits a surface at a point.
Answer:
t = 4.0 min
Explanation:
given data:
diameter of rod = 2 cm
T_1 = 100 degree celcius
Air stream temperature = 20 degree celcius
heat transfer coefficient = 200 W/m2. K
WE KNOW THAT
copper thermal conductivity = k = 401 W/m °C
copper specific heat Cp = 385 J/kg.°C
density of copper = 8933 kg/m3
charateristic length is given as Lc




Biot number is given as 

Bi = 0.0025
As Bi is greater than 0.1 therefore lumped system analysis is applicable
so we have
............1
where b is given as



b = 0.01163 s^{-1}
putting value in equation 1

solving for t we get
t = 4.0 min
Explanation:
Given
initial velocity(v_0)=1.72 m/s

using 
Where v=final velocity (Here v=0)
u=initial velocity(1.72 m/s)
a=acceleration 
s=distance traveled

s=0.214 m
(b)time taken to travel 0.214 m
v=u+at


t=0.249 s
(c)Speed of the block at bottom

Here u=0 as it started coming downward

v=1.72 m/s