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3 years ago

Calorimetry what is the relationship between heat energy and temperature answer key

1 answer:

5 0

<span>Heat energy is the total of heat of an object due to molecular motion inside the object. While temperature is a measure of the average heat or thermal energy of the molecules of a substance. these two terms are related to calorimetry, which is the process of measuring the amount of heat abosorbed or released during a chemical reaction.</span>

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What are the characteristics of S waves?

Reptile [31]

I think the answer is D

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4 years ago

So far in your life, you may have assumed that as you are sitting in your chair right now, you are not accelerating. However, th

tia_tia [17]

Answer:

a) $a=33.73mm/s^{2}$

b) mg>N

c) $\%_{change}=0.343\%$

d) $a=24.07mm/s^{2}$

Explanation:

In order to solve part a) of the problem, we can start by drawing a free body diagram of the presented situation. (see attached picture).

In this case, we know the centripetal acceleration is given by the following formula:

$a_{c}=\omega ^{2}r$

where:

$\omega=\frac{2\pi}{T}$

we know the period of rotation of the earth is about 24 hours, so:

$T=24hr*\frac{3600s}{1hr}=86400s$

so we can now find the angular speed:

$\omega=\frac{2\pi}{86400s}$

$\omega=72.72x10^{-6} rad/s^{2}$

So the centripetal acceleration will be:

$a_{c} =(72.72x10^{-6} rad/s^{2})^{2}(6478x10^{3}m)$

which yields:

$a_{c}=33.73mm/s^{2}$

In order to answer part b, we must draw a free body diagram of us sitting on a chair. (See attached picture.)

So we can do a sum of forces in equilibrium:

$\sum F=0$

so we get that:

$N-mg+ma_{c} = 0$

and solve for the normal force:

$N=mg-ma_{c}$

In this case, we can clearly see that:

$mg>mg-ma_{c}$

therefore mg>N

This is because the centripetal acceleration is pulling us upwards, that will make the magnitude of the normal force smaller than the product of the mass times the acceleration of gravity.

So let's calculate our weight and normal force:

Let's say we weight a total of 60kg, so:

$mg=(60kg)(9.81m/s^{2})=588.6N$

and let's calculate the normal force:

$N=m(g-a_{c})$

$N=(60kg)(9.81m/s^{2}-33.73x10^{-3}m/s^{2})$

N=586.58N

so now we can calculate the percentage change:

$\%_{change} = \frac{mg-N}{mg}x100\%$

so we get:

$\%_{change} = \frac{588.6N-586.58N}{588.6N} x 100\%$

$\%_{change}=0.343\%$

which is a really small change.

d) In order to find this acceleration, we need to start by calculating the radius of rotation at that point of earth. (See attached picture).

There, we can see that the radius can be found by using the cos function:

$cos \theta = \frac{AS}{h}$

In this case:

$cos \theta = \frac{r}{R_{E}}$

so we can solve for r, so we get:

$r= R_{E}cos \theta$

in this case we'll use the average radius of earch which is 6,371 km, so we get:

$r = (6371x10^{3}m)cos (44.4^{o})$

which yields:

r=4,551.91 km

and now we can calculate the acceleration at that point:

$a=\omega ^{2}r$

$a=(72.72x10^{-6} rad/s)^{2}(4,551.91x10^{3}m$

$a=24.07 mm/s^{2}$

5 0

3 years ago

A wave with a frequency of 196 Hz

Marysya12 [62]

Answer:

1372

Explanation:

use the speed formula

Speed=wavelength x frequency

3 0

3 years ago

HELP PLS! What is the power when a crane lifts a piece of pipe from the ground to a certain height, doing 15000 J of work in 25s

Pachacha [2.7K]

Answer: 600watts

Explanation:

Power of crane = ?

Work done by crane = 15000 J

Time taken = 25s

Recall that power is the rate of work done per unit time

i.e Power = work/time

Power = 15000J/25seconds

Power = 600watts

Thus, the power of the crane is 600watts

7 0

3 years ago

Which scientific phenomenon helps scientists determine the chemical composition of some stars? A. absorption of light in a star’

tatyana61 [14]

Answer: The correct answer is A.

Explanation:

Matter can absorb or emit the light. It does not matter what is the source of light. It may be the surface of sun or star.

Atmosphere absorbs the part of white light which is emitted from star. It produces a color spectrum marked by the dark lines. These dark lines are absorption lines. These lines show the characteristics of the elements present in the gas.

The spectrum of star gives the information about the chemical composition of its atmosphere.

Therefore, Absorption of light in star's atmosphere is the scientific phenomenon which helps scientists to determine the chemical composition of some star.

8 0

3 years ago