Answer:
Explanation:
Motor rating is given in horsepower (hp), it will be converted in watt (W).
Standard to install circuit breaker for an electric circuit is usually 20% ~ 25% more than the Rated Current of the circuit
while
Standard to install overload relay for an electric circuit is usually 20% ~ 25% more than the Running Current of the circuit.
So, to find the maximum capacity of the circuit breaker, rated current of the motor will be multiplied by 1.2 ~ 1.25
Step by Step Explanation:
30hp = 22371W (as 1hp = 745.7)
Assuming unity power factor (cosФ=1) and 208V phase to phase voltage:
Rated Power (watt) = √3 . V.I. cosФ
<em>{if 208V is phase to neutral voltage, then use following formula:</em>
<em> Rated Power (watt) = 3 . V.I. cosФ}</em>
Rated Current = <u>62.169A</u>
So, required maximum rating for circuit breaker is:
20% to 25% of the rated current = 62.17*1.2 ~ 62.17*1.25
=74.6A ~ 77.7A
Hence, any breaker between the above mentioned rating will be appropriate.
Answer:
Explanation:
a)
Firstly to calculate the total mass of the can before the metal was lowered we need to add the mass of the eureka can and the mass of the water in the can. We don't know the mass of the water but we can easily find if we know the volume of the can. In order to calculate the volume we would have to multiply the area of the cross section by the height. So we do the following.
100
x 10cm = 1000
Now in order to find the mass that water has in this case we have to multiply the water's density by the volume, and so we get....
x 1000 = 1000g or 1kg
Knowing this, we now can calculate the total mass of the can before the metal was lowered, by adding the mass of the water to the mass of the can. So we get....
1000g + 100g = 1100g or 1.1kg
b)
The volume of the water that over flowed will be equal to the volume of the metal piece (since when we add the metal piece, the metal piece will force out the same volume of water as itself, to understand this more deeply you can read the about "Archimedes principle"). Knowing this we just have to calculate the volume of the metal piece an that will be the answer. So this time in order to find volume we will have to divide the total mass of the metal piece by its density. So we get....
20g ÷ 
= 2.5
c)
Now to find out the total mass of the can after the metal piece was lowered we would have to add the mass of the can itself, mass of the water inside the can, and the mass of the metal piece. We know the mass of the can, and the metal piece but we don't know the mass of the water because when we lowered the metal piece some of the water overflowed, and as a result the mass of the water changed. So now we just have to find the mass of the water in the can keeping in mind the fact that 2.5 overflowed. So now we the same process as in number a) just with a few adjustments.
x (1000 - 2.5) = 997.5g
So now that we know the mass of the water in the can after we added the metal piece we can add all the three masses together (the mass of the can. the mass of the water, and the mass of the metal piece) and get the answer.
100g + 997.5g + 20g = 1117.5g or 1.1175kg
Where are the following awnsers?
X=1/2 at^2
3.1=1/2 a *0.64
a=9.68
v=at
v=0.8*9.6875=7.75
