What is the force that acts on an object and opposes its motion called?

As a system expands, it absorbs 52.5 J of energy in the form of heat from the surroundings. The piston is working against a pres

Kaylis [27]

Answer:

Vi = 0.055 m³ = 55 L

Explanation:

From first Law of Thermodynamics, we know that:

ΔQ = ΔU + W

where,

ΔQ = Heat absorbed by the system = 52.5 J

ΔU = Change in Internal Energy = -102.5 J (negative sign shows decrease in internal energy of the system)

W = Work Done in Expansion by the system = ?

Therefore,

52.5 J = - 102.5 J + W

W = 52.5 J + 102.5 J

W = 155 J

Now, the work done in a constant pressure condition is given by:

W = PΔV

W = P(Vf - Vi)

where,

P = Constant Pressure = (0.5 atm)(101325 Pa/1 atm) = 50662.5 Pa

Vf = Final Volume of System = (58 L)(0.001 m³/1 L) = 0.058 m³

Vi = Initial Volume of System = ?

Therefore,

155 J = (50662.5 Pa)(0.058 m³ - Vi)

Vi = 0.058 m³ - 155 J/50662.5 Pa

Vi = 0.058 m³ - 0.003 m³

7 0

3 years ago

What is unique about the movement of uranus compared to the other outer planets

shusha [124]

Uranus is tilted so far that it essentially orbits the sun on its side, with the axis of its spin nearly pointing at the star

3 0

3 years ago

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Your friend just challenged you to a race through an obstacle course. You know in order to beat him, you must run 30 meters with

seropon [69]

Answer:

Velocity = 0.5 m/s South (A)

Explanation:

You need to determine the average rate of velocity.

The equation you will use is velocity = displacement/time

The displacement is 30m South.

The time is 60 seconds.

Plug into the equation Velocity = 30m South/60 s

Velocity = 0.5 m/s South

3 0

3 years ago

A running back holds 0.25 kg football and runs 100m down the football field. In addition to scoring six points for his team, he

katrin2010 [14]

Answer:

<h2>1) there is no work done on the system</h2><h2>2) A) Using a lever to lift 100 newtons up to 4 meters on to a shelf</h2><h2 /><h2>3) P = 140 W</h2><h2>4) D) In a closed system, a system that isolated from its surrounds, the total energy of the system is conserved</h2>

Explanation:

1) As we know that work done is the product of force and the displacement of the point of action where force is applied

So here we have

$W = 0$

as there is no displacement in the direction where the force is applied

2)As we know that work is product of force and displacement

So we will have

$W_1 = 100 \times 4 = 400 J$

$W_2 = 200 \times 1 = 200 J$

$W_1 = 200 \times 1 = 200 J$

$W_1 = 100 \times 3 = 300 J$

So maximum work is done on

A) Using a lever to lift 100 newtons up to 4 meters on to a shelf

3)

As we know that power is rate of work done

so we have

$P = \frac{W}{t}$

$P = \frac{420}{3}$

$P = 140 W$

4)

As per energy conservation we know that

D) In a closed system, a system that isolated from its surrounds, the total energy of the system is conserved

5 0

3 years ago

Drawing Conclusions Suppose you take a short piece of wire that is not attached to anything and move it up and down in a magneti

Ulleksa [173]

Answer: No. Circuit should be closed.

Explanation:

A changing magnetic field induces emf in a circuit which is placed in it. This induced emf causes current to flow through it. This is given by Faraday's law which states that induced emf results due to rate of change of magnetic flux.

$e = \frac{-d\phi}{dt}= -\frac {dB A} {dt}$

Current flows only through a closed circuit. Thus, when a wire is moved up and down in a magnetic field, it will not induce emf because the wire does not form a loop. It is an open circuit.

4 0

3 years ago

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