Energy from solar radiation may be ________ or taken in by a surface or an object.

Shannon is playing tennis. She swings her racket to hit the tennis ball and sends the ball flying in the same direction.

Gnoma [55]

Answer:

she used force to swing her ball all way back

Explanation:

3 0

3 years ago

The drag force pushes opposite your motion as you ride a bicycle. If you double your speed, what happens to the magnitude of the

PIT_PIT [208]

The drag force is directly proportional to the square of the velocity of motion of the object. So as the speed is doubled, the magnitude of drag force will get quadrupled.

<u>Explanation: </u>

Drag force is the opposing or resisting force acting on any object by the medium in which it is moving. So in this case, you are riding a bicycle, thus the medium can be considered as air.

The formula for calculating drag force is as below:

$\text {Drag force }=\frac{1}{2} \rho v^{2} C_{D} A$

Here, ρ is the density of the air molecules, v is the velocity or speed of the bicycle, CD is the drag coefficient and A is the area of the bicycle.

In the above equation, only the term velocity will be a varying quantity with respect to time and other quantities will remain constant throughout the single situation of riding of bicycle.

So, the equation can be,

$\text { Drag force }=k v^{2}$

Where ,

$k=\frac{1}{2} \rho C_{D} A$ (constant for this whole condition)

Now given the speed of bicycle increased from v to 2v, so the initial drag force will be

$N_{i}=k v^{2}$

After increase in speed, the final drag force will be

$N_{f}=k(2 v)^{2}$

$N_{f}=4 k v^{2}=4 N_{i}$

Thus, if the speed of the bicycle is doubled, the drag force will get increased by four times.

4 0

3 years ago

330 grams of boiling water (temperature 100°C, specific heat capacity 4.2 J/K/gram) are poured into an aluminum pan whose mass i

Alexus [3.1K]

Answer:

T = 74°C

Explanation:

Given Mw = mass of water = 330g, Ma = mass of aluminium = 840g

Cw = 4.2gJ/g°C = specific heat capacity of water and Ca = 0.9J/g°C = specific heat capacity of aluminium

Initial temperature of water = 100°C.

Initial temperature of aluminium = 29°C

When the boiling water is poured into the aluminum pan, heat is exchanged and after a short time the water and aluminum pan both come to thermal equilibrium at a common temperature T.

Heat lost by water equal to the heat gained by aluminium pan.

Mw × Cw×(100 –T) = Ma × Ca × (T–29)

330×4.2×(100– T) = 890×0.9×(T–29)

1386(100 – T) = 801(T –29)

1386/801(100 – T) = T – 29

1.73(100 – T) = T – 29

173 –1.73T = T –29

173+29 = T + 1.73T

202 = 2.73T

T = 202/2.73

T = 74°C

6 0

3 years ago

3 ways pollution gets into neighborhoods

SashulF [63]

Answer:

1. Leaving trash on the ground and not picking it up.

2. Polluting the lake, if your neighborhood has one.

3. Outside people come and dump their waste to your neighborhood.

Hope this helps!

7 0

3 years ago

If the wave being sent is transmitted via an electromagnetic wave explain how the digital signal would be perceived if the signa

Andrej [43]

Answer:

amplitude is commonly for transmitting messages with a radio carrier wave, the amplitude (signal strength) of the carrier wave is varied in proportion to that of the message signal. at the receiving end, the message signal is extracted from the modulated carrier by demodulation. frequency is the encoding of information in a carrier wave with instantaneous frequency. with digital data, the frequency of the carrier is shifted among a set of frequencies, using digits like 1 and 0

6 0

3 years ago