Here’s my work to your question. I used Newton’s Second Law and a kinematics equation to arrive at the answer.
What is the frequency of a wave that has a wavelength of 0.39 m and a speed
1 answer:
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Answer:
a) m=20000Kg
b) v=0.214m/s
Explanation:
We will separate the problem in 3 parts, part A when there were no coals on the car, part B when there is 1 coal on the car and part C when there are 2 coals on the car. Inertia is the mass in this case.
For each part, and since the coals are thrown vertically, the horizontal linear momentum p=mv must be conserved, that is, , were each velocity refers to the one of the car (with the eventual coals on it) for each part, and each mass the mass of the car (with the eventual coals on it) also for each part. We will write the mass of the hopper car as
, and the mass of the first and second coals as
and
respectively
We start with the transition between parts A and B, so we have:
Which means
And since we want the mass of the first coal thrown () we do:
Substituting values we obtain
For the transition between parts B and C, we can write:
Which means
Since we want the new final speed of the car () we do:
Substituting values we obtain
Answer:
Thickness of Styrofoam insulation is 0.02741 m.
Explanation:
Given that,
Height = 0.25 m
Depth = 0.5 m
Power = 400 W
Temperature = 33°C
We need to calculate the area of Styrofoam
Using formula of area
Put the value into the formula
Inner surface temperature of freezer
Outer surface temperature of freezer
We need to calculate the thickness of Styrofoam insulation
Using Fourier law,
Put the value into the formula
Hence, Thickness of Styrofoam insulation is 0.02741 m.