All categories

3 years ago

Please help me. Thank you!

1 answer:

muminat3 years ago

5 0

The faster/slower one i think is faster because the colder the air, the closer the particals are, and for #2 it's because the door is condensed, and the atoms are closer, therefore meaning that the sound particals don't spread, like they would in air, they're more compact (meaning they're) easier to hear, or you just have a good listening ear.

You might be interested in

The count rate of a radioactive source decreases from 1600 counts per minute to 400 counts per minute in 12 hours. What is the h

kirill115 [55]

Answer:

$t_{1/2}=6 h$

Explanation:

Let's use the decay equation.

$A=A_{0}e^{-\lambda t}$

Where:

A is the activity at t time
A₀ is the initial activity
λ is the decay constant

We know that $\lambda=\frac{ln(2)}{t_{1/2}}$

So we have:

$\lambda=\frac{ln(A/A_{0})}{t}$

$\frac{ln(2)}{t_{1/2}}=\frac{ln(A/A_{0})}{t}$

$t_{1/2}=\frac{t*ln(2)}{ln(A/A_{0})}$

$t_{1/2}=6 h$

Therefore, the half-life of the source is 6 hours.

I hope it helps you!

4 0

3 years ago

When bridges are built, special joints must be used because the material of the bridge shrinks, and without these joints, the ma

egoroff_w [7]

Answer:

Option D.

Explanation:

The correct answer is Option D.

The shrinkage of the bridge material is because of thermal contraction.

Thermal contraction and thermal expansion are the phenomena of the bridge material which takes place due to the change in temperature of the atmosphere.

When the temperature of the surrounding increases expansion of the bridge material takes place and when temperature decreases the contraction of the material takes place.

This phenomenon sometimes damages the structure because due to continuous expansion and contraction of materials strength of the bridge decreases.

8 0

4 years ago

YOU GUYS!!!!! I NEED WITH THIS QUESTION PLS PLS!!!!!! YEAH HIS IS DUE IN 10 MINUTES PLS PLS!!!!!!

Ulleksa [173]

Answer: Truck 2, because it has a larger mass than truck 1 (and the same velocity)

Explanation:

We can write the kinetic energy of an object with mass M and velocity V as:

K = (M/2)*V^2

Let's calculate the kinetic energy for each truck:

Now, we can see that both trucks move at the same velocity, but truck 1 has a mass of 5000 pounds, while truck 2 has also a mass of 5000 pounds and an extra of 900 pounds.

Then the total mass of truck 2 is 5000 pounds + 900 pounds = 5900 pounds.

Then both trucks have the same velocity, and truck 2 has a larger mass than truck 1, this implies that truck 2 will have a larger kinetic energy than truck 1.

5 0

3 years ago

PLEASE HELP!!! SCIENCE QUESTION!

Tatiana [17]

C. has to be right, also its the only one that makes sense.
Hope this helps!

5 0

3 years ago

Read 2 more answers

Light of wavelength 630 nm is incident on a long, narrow slit. Determine the angular deflection of the first diffraction minimum

asambeis [7]

Answer:

a) 1.8°

b) 0.18°

c) 0.018°

Explanation:

Wavelength (λ) = 630nm = 630 *10^-9m

The equation that describes the angular deflection of a dark band is

Wsin(βm) = mλ

w = width of the single slit

λ = wavelength of the light

βm = angular deflection of the mth dark band.

a) In order to get the angular deflection of the first dark band for a slit with 0.02mm width, substitute w = 0.02mm = 0.02*10^-3 , m = 1 , λ= 630*10^-9

0.02*10^-3 sin(β1) = 1 * 630*10^-9

Sin(β1) = 630 * 10^-9 / 0.02*10^-3

Sin(β1) = 0.0315

β1 = Sin^-1(0.0315)

= 1.8°

b) substitute w = 0.2mm = 0.2*10^-3 , m = 1 , λ= 630*10^-9

0.2*10^-3 sin(β1) = 1 * 630*10^-9

Sin(β1) = 630 * 10^-9 / 0.2*10^-3

Sin(β1) = 0.00315

β1 = Sin^-1(0.00315)

= 0.18°

c) substitute w = 2mm = 2*10^-3 , m = 1 , λ= 630*10^-9

2*10^-3 sin(β1) = 1 * 630*10^-9

Sin(β1) = 630 * 10^-9 / 2*10^-3

Sin(β1) = 3.15*10^-4

β1 = Sin^-1(3.15*10^-4)

= 0.018°

6 0

3 years ago