Answer:
The rate of transfer of heat is 0.119 W
Solution:
As per the question:
Diameter of the fin, D = 0.5 cm = 0.005 m
Length of the fin, l =30 cm = 0.3 m
Base temperature, 
Air temperature, 
k = 388 W/mK
h = 
Now,
Perimeter of the fin, p = 
Cross-sectional area of the fin, A = 
A = 
To calculate the heat transfer rate:

where

Now,

Centre of Mass then axis of rotation and then moment of inertia. This was the toughest question for your level... happy to help ^_^. It was purely experimental question.
Answer:
a) 378Ns
b) 477.27N
Explanation:
Impulse is the defined as the product of the applied force and time taken. This is expressed according to the formula
I = Ft = m(v-u)
m is the mass = 70kg
v is the final velocity = 5.4m/s
u is the initial velocity = 0m/s
Get the impulse
I = m(v-u)
I = 70(5.4-0)
I = 70(5.4)
I = 378Ns
b) Average total force is expressed as
F = ma (Newton's second law)
F = m(v-u)/t
F = 378/0.792
F = 477.27N
Hence the average total force experienced by a 70.0-kg passenger in the car during the time the car accelerates is 477.27N
Assuming this coin is on earth and that it wasn’t dropped forcefully:
Use the formula d = 1/2at^2. Rewriting using a=g and solving for height h gets us h = 1/2(9.8)t^2.
In this case that would get that the change in height h is 0.5(9.8)(0.3^2) = 0.441 m.
Missing questions: "find the speed of the electron".
Solution:
the magnetic force experienced by a charged particle in a magnetic field is given by

where
q is the particle charge
v its velocity
B the magnitude of the magnetic field

the angle between the directions of v and B.
Re-arranging the formula, we find:

and by substituting the data of the problem (the charge of the electron is

), we find the velocity of the electron: