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3 years ago

The Sun appears to move across the sky during the day. The best explanation for this apparent motion is that Earth is

Physics

2 answers:

Harrizon [31]3 years ago

5 0

Answer:

Explanation:

Effectus [21]3 years ago

4 0

Answer: C

Explanation:

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John throws a baseball from a standing position. Which of the three possible paths will the ball follow?

Marysya12 [62]

Answer: C

Explanation:

Bro this is common sense. Throw something across the room and watch it. It isnt going to be repulsed and fly up. It also isnt going to continue on forever. It will clearly fall and hit the ground

3 0

2 years ago

Read 2 more answers

A radar for tracking aircraft broadcasts a 12 GHz microwave beam from a 2.0-m-diameter circular radar antenna. From a wave persp

NISA [10]

A) 750 m

First of all, let's find the wavelength of the microwave. We have

$f=12GHz=12\cdot 10^9 Hz$ is the frequency

$c=3.0\cdot 10^8 m/s$ is the speed of light

So the wavelength of the beam is

$\lambda=\frac{c}{f}=\frac{3\cdot 10^8 m/s}{12\cdot 10^9 Hz}=0.025 m$

Now we can use the formula of the single-slit diffraction to find the radius of aperture of the beam:

$y=\frac{m\lambda D}{a}$

where

m = 1 since we are interested only in the central fringe

D = 30 km = 30,000 m

a = 2.0 m is the aperture of the antenna (which corresponds to the width of the slit)

Substituting, we find

$y=\frac{(1)(0.025 m)(30000 m)}{2.0 m}=375 m$

and so, the diameter is

$d=2y = 750 m$

B) 0.23 W/m^2

First we calculate the area of the surface of the microwave at a distance of 30 km. Since the diameter of the circle is 750 m, the radius is

$r=\frac{750 m}{2}=375 m$

So the area is

$A=\pi r^2 = \pi (375 m)^2=4.42\cdot 10^5 m^2$

And since the power is

$P=100 kW = 1\cdot 10^5 W$

The average intensity is

$I=\frac{P}{A}=\frac{1\cdot 10^5 W}{4.42\cdot 10^5 m^2}=0.23 W/m^2$

4 0

3 years ago

the cross section area of a hole is 725cm^2. Given that the area of a circle is A=3.14r^2 , find the radius of the hole.

asambeis [7]

$The\ area\ of\ a\ circle\ = \pi r^2 \\ 725\ cm^2 = 3.14r^2 \\
230.57 cm^2 = r^2 \\ \sqrt{230.57\ cm^2} = r \\ \boxed{r = 15.18\ cm}$

7 0

2 years ago

A 600‑kg car accelerates at a rate of 3 m/s2. How much net force is acting on the car to cause this acceleration?

finlep [7]

600(kg) x 3(m/s^2) = 1800N (newtons)

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2 years ago

Provide two ways that objects can become charged

kap26 [50]

Answer:

friction, conduction and induction

Explanation:

Had it in class I had it correct hope this helps.

8 0

2 years ago