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Sunny_sXe [5.5K]
2 years ago
7

Is work being done on a barbell when a weight lifter is holding the barbell over his head?

Physics
1 answer:
AVprozaik [17]2 years ago
7 0
I don’t see any picture sorry I wish I can help tho
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The density of gasoline is 730 kg/m3 at 0°C. Its average coefficient of volume expansion is 9.60 10-4(°C)−1. Assume 1.00 gal of
kipiarov [429]

Answer: 0.4911 kg

Explanation:

We have the following data:

\rho_{0\°C}= 730 kg/m^{3} is the density of gasoline at 0\°C

\beta=9.60(10)^{-4} \°C^{-1} is the average coefficient of volume expansion

We need to find the extra kilograms of gasoline.

So, firstly we need to transform the volume of gasoline from gallons to m^{3}:

V=8.50 gal \frac{0.00380 m^{3}}{1 gal}=0.0323 m^{3} (1)

Knowing density is given by: \rho=\frac{m}{V}, we can find the mass m_{1} of 8.50 gallons:

m_{1}=\rho_{0\°C}V

m_{1}=(730 kg/m^{3})(0.0323 m^{3})=23.579 kg (2)

Now, we have to calculate the factor f by which the volume of gasoline is increased with the temperature, which is given by:

f=(1+\beta(T_{f}-T_{o})) (3)

Where T_{o}=0\°C is the initial temperature and T_{f}=21.7\°C is the final temperature.

f=(1+9.60(10)^{-4} \°C^{-1}(21.7\°C-0\°C)) (4)

f=1.020832 (5)

With this, we can calculate the density of gasoline at 21.7\°C:

\rho_{21.7\°C}=730 kg/m^{3} f=(730 kg/m^{3})(1.020832)

\rho_{21.7\°C}=745.207 kg/m^{3} (6)

Now we can calculate the mass of gasoline at this temperature:

m_{2}=\rho_{21.7\°C}V (7)

m_{2}=(745.207 kg/m^{3})(0.0323 m^{3}) (8)

m_{2}=24.070 kg (9)

And finally calculate the mass difference \Delta m:

\Delta m=m_{2}-m_{1}=24.070 kg-23.579 kg (10)

\Delta m=0.4911 kg (11) This is the extra mass of gasoline

6 0
3 years ago
True or False : Waves lose most of their energy when traveling across the ocean.
klemol [59]

Answer:

true

Explanation:

that's the answear

3 0
2 years ago
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Which explains why a gas does not have a fixed shape?
mafiozo [28]
A gas doesn't have a fixed shape because the amount of space between the molecules in gas can change easily. B. the particles are not compressible
8 0
3 years ago
IV) Fill in the blanks:
Vlada [557]

1.) equal volume of different substances have "different" masses.

2.)The more closely packed arrangement the particles of a substance have, "increases" its density.

3.)the SI unit of power is "Watts".

4.)an iron nail sinks in water but floats on " mercury ".

5.)balloons used for advertisements are filled with " helium" gas.

6.)"Conduction" is the primary mode of heat transfer in liquid and gases.

I hope this helps you...

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Question 1 of 10
ss7ja [257]

Answer: ME= E total - E thermal

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