Answer:
a. 9947 m
b. 99476 times
c. 2*10^11 molecules
Explanation:
a) To find the mean free path of the air molecules you use the following formula:

R: ideal gas constant = 8.3144 Pam^3/mol K
P: pressure = 1.5*10^{-6} Pa
T: temperature = 300K
N_A: Avogadros' constant = 2.022*10^{23}molecules/mol
d: diameter of the particle = 0.25nm=0.25*10^-9m
By replacing all these values you obtain:

b) If we assume that the molecule, at the average, is at the center of the chamber, the times the molecule will collide is:

c) By using the equation of the ideal gases you obtain:

Answer:
Honestly overall i think it looks fantastic
Explanation:
It looks like some really nice clean craftsmanship and i love the use of some different colors for some drawers to make it pop. the only con that i can possibly think of is that with it being wood and you moving it from place to place, some rubber feet or something that would prevent it from scratching/damaging anything else if it doesn't already (cant really see under it). other then that one thing i think it looks really good. well done.
Solution :
Given :
The number of blows is given as :
0 - 6 inch = 4 blows
6 - 12 inch = 6 blows
12 - 18 inch = 6 blows
The vertical effective stress 


Now,

corrected N - value of overburden
effective stress at level of test
0 - 6 inch, 
= 9.86
6 - 12 inch, 
= 14.8
12 - 18 inch, 
= 14.8

= 13.14
= 13
Answer:
(d) all of the above
Explanation:
before cutting the screw threads the operator should lubricate all of the machine parts given in the option that is lead screw and gearbox , the ways and the cross slide and the carriage and half-nuts. we should use lubrication because it reduces the overall system friction and if friction is reduced then heat generated due to friction is also decreases which is beneficial
so option (D) will be correct because we need lubricate in all the given parts