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3 years ago

Exposure to what kind of energy is sensed by human skin as warmth?

1 answer:

5 0

Ultraviolet rays.

The sun emits UV rays which reach the earth by radiation, heats the earth. The harmful rays are reflected back.
Hope it helped!

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Describe a device that transforms thermal energy into<br> another useful form.<br> tes that

spin [16.1K]

Answer: heat engine

Explanation:

4 0

2 years ago

A whale comes to the surface to breathe and then dives at an angle of 20.0 ∘ below the horizontal (see the figure (Figure 1)). I

Bond [772]

Answer:

The question is missing something it doesn't say how fast down its going and doesn't show the figure sorry for wasting an answer

7 0

2 years ago

You are standing in a building whose height (40m) you throw a ball downward at a angle of -30 at a speed of (10m/s) acceleration

jeyben [28]

Answer: 3.41 s

Explanation:

Assuming the question is to find the time $t$ the ball is in air, we can use the following equation:

$y=y_{o}+V_{o}sin \theta t-\frac{1}{2}gt^{2}$

Where:

$y=0m$ is the final height of the ball

$y_{o}=40 m$ is the initial height of the ball

$V_{o}=10 m/s$ is the initial velocity of the ball

$t$ is the time the ball is in air

$g=9.8 m/s^{2}$ is the acceleration due to gravity

$\theta=30\°$

Then:

$0 m=40 m+(10 m/s)(sin(30\°))t-\frac{1}{2}9.8 m/s^{2}t^{2}$

$0 m=40 m+5m/s t-4.9 m/s^{2}t^{2}$

Multiplying both sides of the equation by -1 and rearranging:

$4.9 m/s^{2}t^{2}-5m/s t-40 m=0$

At this point we have a quadratic equation of the form $at^{2}+bt+c=0$ , which can be solved with the following formula:

$t=\frac{-b \pm \sqrt{b^{2}-4ac}}{2a}$

Where:

$a=4.9$

$b=-5$

$c=-40$

Substituting the known values:

$t=\frac{-(-5) \pm \sqrt{(-5)^{2}-4(4.9)(-40)}}{2(4.9)}$

Solving the equation and choosing the positive result we have:

$t=3.41 s$ This is the time the ball is in air

5 0

3 years ago

When a wave is acted upon by an external damping force what happens to the energy of the wave

Nimfa-mama [501]

Answer:

A-the energy of the wave decreases gradually

Explanation:

when a wave is acted upon by an external damping force the energy of the wave decreases gradually.

The energy degrades into the form of heat which is considered to be of less value and use. The reason is because it disperses and spreads more widely.

So therefore it end up as heat with a little sound but that is close to none because that too disperses into heat i.e. decreased form of energy.

4 0

3 years ago

Please help me anything will help

spin [16.1K]

Your answer is C) The speed of sound is higher in solids than in liquids.

6 0

2 years ago