All categories

3 years ago

6. An unknown material has a normal melting/freezing point of 225.0 °C, and the liquid

Physics

1 answer:

kkurt [141]3 years ago

7 0

Answer:

19.4 kJ/kg

Explanation:

I'm assuming you meant that the melting/freezing point is -25.0 °C.

Heat gained by the unknown material = heat lost by the oil and aluminum

mL + mCΔT = -(mCΔT + mCΔT)

First, let's find the amount of heat gained by the unknown material:

(0.100 kg) L + (0.100 kg) (160 J/kg/°C) (20.0°C − (-25.0°C))

(0.100 kg) L + 720 J

The heat lost by the oil:

(0.100 kg) (2430 J/kg/°C) (20.0°C − 27.0°C)

-1701 J

The heat lost by the aluminum:

(0.150 kg) (910 J/kg/°C) (20.0°C − 27.0°C)

-955.5 J

Therefore:

(0.100 kg) L + 720 J = -(-1701 J + (-955.5 J))

(0.100 kg) L + 720 J = 2656.5 J

(0.100 kg) L = 1936.5 J

L = 19365 J/kg

L = 19.4 kJ/kg

You might be interested in

A physician might deal with potential problems associated with the ________ characteristic of services by providing physical cue

asambeis [7]

I believe Intangibility is the answer! :P I hope this helps!

8 0

3 years ago

According to Kepler's Second Law the radius vector drawn from the Sun to a planet Multiple Choice is the same for all planets. s

Mademuasel [1]

Answer:

sweeps out equal areas in equal times.

Explanation:

As we know that there is no torque due to Sun on the planets revolving about the sun

so we will have

$\tau_{net} = 0$

now we have

$\frac{dL}{dt}= 0$

now we also know that

$Area = \frac{1}{2}r^2d\theta$

so rate of change in area is given as

$\frac{dA}{dt} = \frac{1}{2}r^2\frac{d\theta}{dt}$

so we will have

$\frac{dA}{dt} = \frac{1}{2}r^2\omega$

$\frac{dA}{dt} = \frac{L}{2m}$

since angular momentum and mass is constant here so

all planets sweeps out equal areas in equal times.

4 0

3 years ago

horrorfan [7]

Answer:

B. 6HgO → 6Hg + 3O $_{2}$

Explanation:

A decomposition reaction is a reaction in which a single reactant is broken down into 2 or more products.

6 0

3 years ago

Is V directly proportional to I (From V=IR)??<br>Or is V inversely proportional to I (From P=IV) ???

ziro4ka [17]

First of all, I is proportional V according to the Ohm's Law. R is merely a constant you need to obtain an equation. However, it is true that R changes with temperature and pressure, therefore Ohm's Law is only applicable in an invariable environment. Also this constant R is different for different materials.

So, do not get confused.

Ohm's law is not a universal law, please remember that as well. Some materials do not follow it and we call them non-ohmic conductors. I hope I helped! ^-^

3 0

2 years ago

So lost on this one number 1 ?

kirza4 [7]

Read each statement, one at a time, and form the picture in your mind.

<em>Statement #1</em> should make you feel all warm and fuzzy inside.

Statements #2, #3, and #4 should make your red flag wave on the inside, and should make you giggle on the outside when you realize how absurd each of those is.

5 0

2 years ago