The answer is b, I hope this helps you
Answer:

Explanation:
To solve this problem we use the expression for the temperature film

Then, we have to compute the Reynolds number

Re<5*10^{5}, hence, this case if about a laminar flow.
Then, we compute the Nusselt number

but we also now that

but the average heat transfer coefficient is h=2hx
h=2(8.48)=16.97W/m^{2}K
Finally we have that the heat transfer is

In this solution we took values for water properties of
v=16.96*10^{-6}m^{2}s
Pr=0.699
k=26.56*10^{-3}W/mK
A=1*0.5m^{2}
I hope this is useful for you
regards
Answer:
18 teeth/inch
Explanation:
Given that: i. driver gear has 8 teeth and diametral pitch of 6 teeth/inch.
ii. follower gear has 24 teeth.
Let the followers diametral pitch be represented by x.
Then,
8 teeth ⇒ 6 teeth/inch
24 teeth ⇒ x teeth/inch
So that;
x = 
= 
= 18 teeth/inch
The diametral is 18 teeth/inch