Ask question

Ask question

All categories

3 years ago

15

1. Which of the following is a physical change? (2 points) A newspaper burns when placed in a fire. An iron chair rusts when lef

t outside. A sample of water boils and releases gas. A plant changes carbon dioxide and water into sugar.

2 answers:

andre [41]3 years ago

4 0

A. It is changing state, color. Etc.

Brilliant_brown [7]3 years ago

3 0

<span>An iron chair rusts when left outside.</span>

You might be interested in

By how much will the water temperature increases if 1046 J of heat energy are added. The specific heat of water is 4.184 J/g • °

Brilliant_brown [7]

Answer:

Option A

250 degrees Celcius

Explanation:

If 1046J of heat energy is added to water, the water will experience a rise in temperature, at a rate that is directly proportional to its specific heat capacity.

Mathematically, this can be seen as $Q=C\Delta T$

Where C = specific heat of water = 4.184 J/g • °C.

Q = heat energy = 1046 J

$\Delta T =1046/4.148=250 degrees Celcius$

Therefore, the increase in temperature that will be experienced, is for 250 degrees Celcius

8 0

2 years ago

A man weighing 75 kg takes 5 minutes to reach a height of 5 m when he climbs a staircase. What is his power?

Naddika [18.5K]

Answer: B. 12.25 W

please give brainliest!

Explanation:

1) Force = Weight = 75 x 9.8 = 735 N

2.)Work = Force x Height = 735 x 5 = 3675 J

3.)Power = Work / Time = 3675 / (5 x 60) = 12.25 W

4 0

3 years ago

What is the total probability of finding a particle in a one-dimensional box in level n = 4 between x = 0 and x = L/8?

Lubov Fominskaja [6]

Answer:

P = 1/8

Explanation:

The wave function of a particle in a one-dimensional box is given by:

$\psi = \sqrt \frac{2}{L} sin(\frac{n \pi x}{L})$

Hence, the probability of finding the particle in the one-dimensional box is:

$P = \int_{x_{1}}^{x_{2}} \psi^{2} dx$

$P = \int_{x_{1}}^{x_{2}} (\sqrt \frac{2}{L} sin(\frac{n \pi x}{L}))^{2} dx$

$P = \frac{2}{L} \int_{x_{1}}^{x_{2}} (sin^{2}(\frac{n \pi x}{L}) dx$

Evaluating the above integral from x₁ = 0 to x₂ = L/8 and solving it, we have:

$P = \frac{2}{L} [\frac{L}{16} (1 - 4\frac{sin(\frac{n \pi}{4})}{n \pi})]$

$P = \frac{1}{8} (1 - 4\frac{sin(\frac{n \pi}{4})}{n \pi})$

Solving for n=4:

$P = \frac{1}{8} (1 - 4\frac{sin(\frac{4 \pi}{4})}{4 \pi})$

$P = \frac{1}{8} (1 - \frac{sin (\pi)}{\pi})$

$P = \frac{1}{8}$

I hope it helps you!

7 0

3 years ago

A sample of propane (C3H8) has a mass of 0. 47 g. The sample is burned in a bomb calorimeter that has a mass of 1. 350 kg and a

Nady [450]

The amount of heat released by the sample has been 22.54 kJ. Thus, option C is correct.

The specific heat has been defined as the amount of heat required to raise the temperature of 1 gram of substance by 1 degree Celsius.

The specific heat has been expressed as:

$q=mc\Delta T$

<h3 /><h3>Computation for the heat absorbed</h3>

The iron and calorimeter are in side the closed system. Thus, the energy released by the sample, has been equivalent to the energy absorbed by the calorimeter.

$q_{released}=q_{absorbed}\\
q_{released}=m_{calorimeter}\;c_{calorimeter}\;\Delta T$

The given mass of calorimeter has been, $m_{calorimeter}=1350\;\rm g$

The specific heat of the calorimeter has been, $c_{calorimeter}=5.82\;\rm J/g^\circ C$

The change in temperature of the calorimeter has been, $\Delta T=2.87^\circ \rm C$

Substituting the values for heat released:

$q_{released}= 1350\;\text g\;\times\;5.82\;\text J/\text g^\circ \text C\;\times\;2.87^\circ \text C\\
q_{released}=22,549.5\;\text J\\
q_{released}}=22.54\;\rm kJ$

The amount of heat released by the sample has been 22.54 kJ. Thus, option C is correct.

Learn more about specific heat, here:

brainly.com/question/2094845

6 0

2 years ago

PLS HELP ME I WILL GIVE BRAINLIEST TO U I JUST NEED ANSWERS ASAP

elena55 [62]

Answer:

is this multiple choice just wondering

4 0

3 years ago