All categories

3 years ago

Which is heavier—warm air or cold air?

1 answer:

5 0

Cold air. This is because there is more water in hot air due to its capacity for humidity and the water particles are actually less massive than the particles in cold air.

You might be interested in

What are the mechanics of a dunk tank?

mr_godi [17]

Step 1

Get a big plastic tank filled with water. You can use an industrial sized barrel, storage tank or some sort of above ground pool.

Step 2

Take a large board, wide enough to fit across the tank, and cut out a rectangular piece from the middle for the seat.

Step 3

Attach the seat back into the support board with heavy duty hinges at the back so that it can swing down freely.

Step 4

Attach a heavy duty door latch of the type used in public restrooms to the underside of the seat so that, when the latch is closed, the seat can't swing down. Use screws and epoxy to attach and reinforce it.

Step 5

Horizontally mount a bicycle wheel on the far side of the tank. It should be mounted on the same side that the latch is going to be on. Mount it in such a way that it will spin freely.

Step 6

Create a target. You can use a simple piece of wood, a caricature, or anything else. The point is to make something for people to throw at.

Step 7

Nail the target to the end of the lever arm.

Step 8

Attach a large lever arm to the bicycle wheel. This is the board that the target is going to be mounted on, so it should reach out far to the side of the wheel.

Step 9

Cover the seat board with something comfortable to sit on. This is going to be the seat, so you want to use something padded. Foam attached with contact cement would be an excellent choice, but even a thin layer of cloth or vinyl would work.

Step 10

Attach the longer board across the top of the tank so that the other board swings downward when released. Depending on what the tank is made of, you could use epoxy, nails, brackets or any combination.

Step 11

Attach a string from the bicycle wheel to the latch so that, when the lever arm swings back, the latch pulls out and releases the seat.

Step 12

Fill the pool with water...

3 0

3 years ago

By what factor is the intensity of sound at a rock concert louder than that of a whisper when the two intensity levels are 120 d

77julia77 [94]

Answer:

The intensity of sound at rock concert is 10¹⁰ greater than that of a whisper.

Explanation:

The intensity of sound is given by;

$I(dB) = 10Log(\frac{I}{I_o} )$

where;

I is the intensity of the sound

I₀ is the threshold of sound intensity = 1 x 10⁻¹² W/m²

The intensity of sound at a rock concert

$120 = 10Log(\frac{I}{1*10^{-12}} )\\\\12 = Log(\frac{I}{1*10^{-12}} )\\\\\frac{I}{1*10^{-12}} = 10^{12}\\\\I = 1*10^{-12} *10^{12}\\\\I = 1*10^0\\\\I =1 \ W/m^2$

The intensity of sound of a whisper

$20 = 10Log(\frac{I}{1*10^{-12}} )\\\\2 = Log(\frac{I}{1*10^{-12}} )\\\\\frac{I}{1*10^{-12}} = 10^{2}\\\\I = 1*10^{-12} *10^{2}\\\\I = 1*10^{-10}\\\\I =10^{-10} \ W/m^2$

Thus, the intensity of sound at rock concert is 10¹⁰ greater than that of a whisper.

4 0

3 years ago

How many electrons have been removed from a positively charged electroscope if it has a net charge of 6x10-11?

faltersainse [42]

Answer:

<h3>Because one Coulomb of charge is an abnormally large quantity of charge, the units of microCoulombs (µC) or nanoCoulombs (nC) are more commonly used as the unit of measurement of charge. To illustrate the magnitude of 1 Coulomb, an object would need an excess of 6.25 x 1018 electrons to have a total charge of -1 C.</h3>

Explanation:

<h3><em><u>mark as brainliast</u></em></h3><h3><em><u>indian </u></em><em><u>genius </u></em><em><u>s</u></em><em><u>a</u></em><em><u>r</u></em><em><u>thak</u></em></h3>

4 0

3 years ago

. Consider a fully extended arm that is rotating about the shoulder such that with a shoulder-to-hand length of 30 cm. If the ar

Rainbow [258]

Answer:

13.309 m/s²

Explanation:

Length from shoulder to hand, l = 30 cm = 0.3 m

initial velocity, u = 1 m/s

final velocity, v = 2.5 m/s

time, t = 3 s

Let the tangential acceleration is a.

by using first equation of motion

v = u + at

2.5 = 1 + 3 a

a = 0.5 m/s²

Let the centripetal acceleration is a'.

a' = v'²/l

a' = 2 x 2 / 0.3

a' = 13.3 m/s²

The tangential acceleration and the centripetal acceleration are both perpendicular to each other. So, the net acceleration is given by

$A=\sqrt{a^{2}+a'^{2}}$

$A=\sqrt{0.5^{2}+13.3^{2}}$

A = 13.309 m/s²

3 0

3 years ago

Hans Langseth's beard measured 5.33 m in 1927. Consider two charges, q1 = 2.42 nC and an unspecified charge, q2, are separated 5

schepotkina [342]

Answer:

-7.89 * 10^(-9) C

Explanation:

Parameters given:

q1 = 2.42 nC = 2.42 * 10^(-9) C

Distance between q1 and q2 = 5.33 m

q3 = 1.0 nC = 1 * 10^(-9) C

Distance between q1 and q3 = 1.9 m

Distance between q2 and q3 = 5.33 - 1.9 = 3.43 m

The net force acting on q3 is:

F = F(q1, q3) + F(q2, q3)

F = (k*q1*q3)/1.9² + (k*q2*q3)/3.43²

F = (9 * 10^(9) * 2.42 * 10^(-9) * 1 * 10^(-9))/3.61 + (9 * 10^(9) * q2 * 1 * 10^(-9))/11.7649

F = 6.033 * 10^(-9) + 0.765*q2

If the net force is zero:

0 = 6.033 * 10^(-9) + 0.765*q2

-0.765*q2 = 6.033 * 10^(-9)

=> q2 = -[6.033 * 10^(-9)]/0.765

q2 = -7.89 * 10^(-9) C

3 0

3 years ago