Ask question

Ask question

All categories

2 years ago

14

What property of light is suggested by the formation of shadows

1 answer:

Mandarinka [93]2 years ago

3 0

Answer:

The reflection and rectilinear propagation of light helps in the formation of shadows and also tells light doesn't penetrate opaque materials.

You might be interested in

How many chromosomes does a Human have? And how is a baby's gender determined? (Example: For the baby to be a boy, it would need

Ad libitum [116K]

A human has 46 chromosome pairs. For a baby to be a boy its needs to have a xy chromosome and for it to be a girl it has to be xx.

4 0

3 years ago

Read 2 more answers

Because of inertia, it will be ____ to stop a larger object than a smaller object if they are both moving at the same speed.

strojnjashka [21]

Answer:

harder

heavier objects resist change more than lighter objects.

8 0

3 years ago

Read 2 more answers

The Earth revolves around the sun in a nearly circular orbit. Please select the best answer from the choices provided T F

Verdich [7]

The Earth does revolves around the sun in a nearly circular orbit so the answer is T

6 0

2 years ago

Read 2 more answers

How has the farming industry been affected by the use of fossil fuels?

Inessa [10]

Answer:

Large quantities of fossil-fuel are needed to drive heavy agricultural equipment, processing food, refreeze food throughout transportation, manufacture packaging products, and manufacture and freight chemical supplies including fertilisers and pesticides.

Explanation:

Large quantities of fossil-fuel are needed to drive heavy agricultural equipment, processing food, refreeze food throughout transportation, manufacture packaging products, and manufacture and freight chemical supplies including fertilisers and pesticides. fossil duel rates also affect the cost of fertilizer and crop production material.

5 0

3 years ago

20. An electron with total energy 5 eV approaches a potential barrier of height 20 eV. If the probability that the electron tunn

Harrizon [31]

Answer:

The width L of the barrier is b. 0.116nm

Explanation:

This is a case of tunnel effect when the probability is less than one.

First of all you find all the information the problem gives you:

Electron's total energy E=5eV

Height of potential barrier U=20eV

Crossing Probability T=0.03

Width of the barrier L=unknown

Then you need to find the equations to use in cases in which the probability is less than 0, so you have:

$T=Ge^{-2kL}$

$G=16\frac{E}{U}(1-\frac{E}{U})$

$k=\frac{\sqrt{2m(U-E)}}{h}$ where m is the mass of the electron, $m=9.11*10^{-31}Kg$ , and h is the Planck constant, $h=1.054*10^{-34}J.s$

First we find G, we have:

$G=16(\frac{5.0eV}{20eV})(1-\frac{5.0eV}{20eV})$

$G=4(1-0.25)=3$

Now, to solving k, we need to find the difference (U-E) :

U - E = 20eV - 5eV = 15eV

$15eV*\frac{1.60218*10^{-19}J}{1eV} =2.403*10^{-18}J$

Then, we can find k:

$k=\frac{\sqrt{2m(U-E)}}{h}$

$k=\frac{\sqrt{2(9.11*10^{31}kg)(2.403*10^{-18}J)}}{1.054*10^{-34}\frac{J}{s}}$

$k=1.98*10^{10}$

Finally, we solve for L the probability equation T:

$T=Ge^{-2kL}$

$\frac{T}{G}=e^{-2kL}$

$ln(\frac{T}{G})=ln(e^{-2kL})$

$ln(\frac{T}{G})=-2kL$

$L=\frac{ln(\frac{T}{G})}{-2k}$

And replacing values for T, G and k, we can find the width of the barrier:

$L=\frac{ln(\frac{0.03}{3})}{-2(1.98*10^{10})}m$

$L=1.16*10^{-10}m*\frac{1*10^{9}nm}{1m}$

L=0.116nm

5 0

3 years ago