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stealth61 [152]
3 years ago
6

Why is an echo weaker than the original sound? 1. The echo has a shorter wavelength than the original sound due to the reflection

. 2. The echo has a smaller amplitude than the original sound because sound spreads and its intensity decreases with distance. 3. The echo has a longer wavelength than the original sound due to the reflection. 4. The echo has a higher frequency than the original sound due to the reflection.
Physics
1 answer:
jasenka [17]3 years ago
5 0
The echo is weaker than the original sound since the echo has a smaller amplitude than the original sound because sound spreads and its intensity decreases with distance. For example, when the sound from a speaker is heard and is compared to its echo, the echo heard has a lower amplitude than the actual sound. 
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Which of these statements partially defines law?
xz_007 [3.2K]

Answer: I dont see the option choices

Explanation:

5 0
3 years ago
Estimate how far apart the rays of deepest red and deepest violet light are as they exit the bottom surface. assume nred = 1.57
Harlamova29_29 [7]
We begin by noting that the angle of incidence is the one that's taken with respect to the normal to the surface in question. In this case the angle of incidence is 30. The material is Flint Glass according to the original question. The refractive indez of air n1=1, the refractive index of red in flint glass is nred=1.57, finally for violet in the glass medium is nviolet=1.60. Snell's Law dictates:
n_1sin(\theta_1)=n_2sin(\theta_2)
Where \theta_2 differs for each wavelenght, that means violet and red will have different refractive indices in the glass.
In the second figure provided details are given on which are the angles in question, \Delta x is the distance between both rays.
\theta_{2red}=Asin(\frac{sin(30)}{1.57})\approx 18.5705
\theta_{2violet}=Asin(\frac{sin(30)}{1.60})\approx 18.21
At what distance d from the incidence normal will the beams land at the bottom?
For violet we have:
d_{violet}=h.tan(\theta_{2violet})\approx 0.0132m
For red we have:
d_{red}=h.tan(\theta_{2red})\approx 0.0134m
We finally have:
\Delta x=d_{red}-d_{violet}\approx2.8\times10^{-4}m


6 0
3 years ago
IF YOU CAN TRY TO ANSER THIS AS FAST AS YOU CAN THANKYOU. Explain the relationship between physical activity, fitness, health, a
Rom4ik [11]

Answer:When losing weight, more physical activity increases the number of calories your body uses for energy or “burns off.” The burning of calories through physical activity, combined with reducing the number of calories you eat, creates a “calorie deficit” that results in weight loss.

Most weight loss occurs because of decreased caloric intake. However, evidence shows the only way to maintain weight loss is to be engaged in regular physical activity.

Most importantly, physical activity reduces risks of cardiovascular disease and diabetes beyond that produced by weight reduction alone.

Physical activity also helps to–

Maintain weight.

Reduce high blood pressure.

Reduce risk for type 2 diabetes, heart attack, stroke, and several forms of cancer.

Reduce arthritis pain and associated disability.

Reduce risk for osteoporosis and falls.

Reduce symptoms of depression and anxiety.

Top of Page

How much physical activity do I need?

Photo: Women exercising in a swimming pool

When it comes to weight management, people vary greatly in how much physical activity they need. Here are some guidelines to follow:

To maintain your weight: Work your way up to 150 minutes of moderate-intensity aerobic activity, 75 minutes of vigorous-intensity aerobic activity, or an equivalent mix of the two each week. Strong scientific evidence shows that physical activity can help you maintain your weight over time. However, the exact amount of physical activity needed to do this is not clear since it varies greatly from person to person. It’s possible that you may need to do more than the equivalent of 150 minutes of moderate-intensity activity a week to maintain your weight.

To lose weight and keep it off: You will need a high amount of physical activity unless you also adjust your diet and reduce the amount of calories you’re eating and drinking. Getting to and staying at a healthy weight requires both regular physical activity and a healthy eating plan.

Explanation:

3 0
3 years ago
Read 2 more answers
A basketball player can leap upward 0.43 m. how long does he remain in the air? use an acceleration due to gravity of 9.80 m/s2
MArishka [77]
From the equations of linear motion,
v² = u² + 2as where v is the final velocity, u is the initial velocity and a is the gravitational acceleration, and s is the displacement,
Thus, v² = u² -2gs, but v=0
hence, u² = 2gs
                = 2×9.81×0.43
                = 8.4366
            u = √8.4366
               =2.905 m/s
Hence the initial velocity is 2.905 m/s
 Then using the equation v= u +gt .
Therefore, v = u -gt. (-g because the player is jumping against the gravity)
but, v = 0
Thus, u= gt
Hence, t = u/g
              = 2.905/9.81
              = 0.296 seconds


3 0
3 years ago
A 75-kg piano is hoisted on a crane and delivered throughout the window of a 6th story apartment (20 meters above ground). What
ipn [44]

Answer:

P = 14700 J

Explanation:

Given that,

Mass of a piano, m = 75 kg

It is delivered throughout the window of a 6th story apartment which is 20 m above the ground.

We need to find the potential energy of the piano. It is given by :

P = mgh

Putting all the values,

P = 75 kg × 9.8 m/s² × 20 m

P = 14700 J

So, the potential energy of the piano is 14700 J.

7 0
3 years ago
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