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4 years ago

Classify the statements as correct or incorrect.

Physics

2 answers:

alexandr402 [8]4 years ago

6 0

Explanation:

A thermometer does measure the temperature of a body and not the heat. It is known that temperature is a measure of average kinetic energy.

Therefore, the statement a thermometer measures the average kinetic energy of a substance is correct.

Heat is a form of energy as it can make a colder substance become hot and it moves from one place to another. Thus, the statement heat is a form of energy is correct.

Also, heat flows from hotter substance to colder substance. Hence, the statement heat flows from a colder substance to a hotter substance is correct.

Convection is a property of fluids or gases which makes less denser (hot) material to rise and more denser (colder) material to sink.

Therefore, the statement convection occurs only in liquids and gases is correct.

All substances radiate heat is an incorrect statement. For example, a thermos bottle does not radiate heat.

Temperature of our body is about 98.4 degree celsius and hence we can conclude that the statement our body temperature is always equal to the temperature around us is incorrect.

Marina CMI [18]4 years ago

6 0

Answer:

Correct:

-Heat is a form of energy.

-Heat flows from a colder substance a hotter substance.

-Convection occurs only in liquids and gases.

-All substances radiate heat.

Incorrect:

-Our body temperature is always equal to the temperature around us.

-A thermometer measures the average kinetic energy of a substance.

Explanation:

I just took the test!! :)

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4 years ago

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3 years ago

When using a calorimeter, the initial temperature of a metal is 70.4C. The initial temperature of the water is 23.6C. At the end

Sunny_sXe [5.5K]

1) 29.8 C

At the beginning, the metal is at higher temperature (70.4 C) while the water is at lower temperature (23.6 C). When they are put in contact, the metal transfers heat to the water, until they reach thermal equilibrium: at thermal equilibrium the two objects (the metal and the water have same temperature). Therefore, since the temperature of the water at thermal equilibrium is 29.8 C, the final temperature of the metal must be the same (29.8 C).

2) 6.2 C

The temperature change of the water is given by the difference between its final temperature and its initial temperature:

$\Delta T = T_f - T_i$

where

$T_f = 29.8 C\\T_i = 23.6 C$

Substituting into the formula,

$\Delta T=29.8 C-23.6 C=6.2 C$

And the positive sign means that the temperature of the water has increased.

3) -40.6 C

The temperature change of the metal is given by the difference between its final temperature and its initial temperature:

$\Delta T = T_f - T_i$

where

$T_f = 29.8 C\\T_i = 70.4 C$

Substituting into the formula,

$\Delta T=29.8 C-70.4 C=-40.6 C$

And the negative sign means the temperature of the metal has decreased.

5 0

4 years ago

Read 2 more answers

A pilot is flying a small airplane at 40 m/s in a circular path with a radius of 200 m. The pilot has a mass of 80.5 kg

g100num [7]

Try This Method(substitute your values)
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F= mv^2/r 
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4 0

3 years ago

Design an experiment to test the rate at which temperature changes for two different masses (amounts) of water.

mrs_skeptik [129]

Answer:Experimental Question: How does the amount of a substance affect the rate at which temperature changes?

It depends on the conductivity of the material. If the shift is extreme, the temperature near the heating / cooling source will be similar to the temperature of the heating / cooling source and it will take time for the remainder of the material to rise to temperature. It will depend on the conductivity of the material.

Hypothes is:

Materials List:

• digital stopwatch

• 250ml beaker

• rubber bung

• thermometer

• bunsen burner

• tripod

• gauze

• retort stand and clamp

• goggles

Safety Procedures *:

1. Adult supervision is required.

2. Wear safety goggles, apron, and closed-toe shoes.

3. Do not wear baggy sleeves or dangling jewelry. Tie long hair back.

4. Use hot pads or oven mitts to handle hot objects.

5. Do not reach over a hot burner.

6. Do not leave the experiment unattended.

7. Clean up spills immediately.

8. Report any injuries to your Learning Coach or adult supervisor immediately

Experimental Procedures :

• Fill an empty beaker with exactly 150ml of water (check side-scale of beaker)

• Set up apparatus as shown above. Ensure the thermometer is about 2cm above the bottom of the beaker.

• Light the bunsen burner and put on a blue flame. Heat up the water.

• When the temperature on the thermometer has reached 90°C, immediately switch off the burner.

• Start the stopwatch and time for 5.0 minutes.

• Read the thermometer value at the 5.0 minute mark.

• Before repeating the experiment, check the level of water is still 150ml

Data Table:

Start Temperature of Water (°C) Temperature after 5min (°C) Drop in Temperature

(°C) Average Rate of Cooling x 1000 (°C/s)

80 70 10 17

75 66 9 15

70 62 8 13

65 59 6 10

60 55 5 8

Analysis:

Conclusions : There is a strong correlation between the average rate of cooling and the start temperature: the greater the start temperature, the faster the average rate of cooling.

Explanation:

use quillbot or this will be considered plagerism

3 0

3 years ago