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3 years ago

A ball rolls of a building that is 100 m high. Calculate the time it takes to hit the ground.

Physics

1 answer:

fgiga [73]3 years ago

4 0

Answer:

2as=v2-u2

2000=v2

V=44

V=u+at

44/10=t

T=4.4seconds

Explanation:

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When a system fails it _____ our other systems causing us to be sick.

krok68 [10]

Answer:

c) affects

Explanation:

im like 90% sure

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3 years ago

Write four (4) strategies on how can we manage land use around South Florida. For each strategy, explain it's benefits to the en

a_sh-v [17]

Answer:

What are some ways we can improve on our land use?

- Avoid deforestation and close the forest frontier.

The first-order priority is to end deforestation by closing the "forest frontier" or intact forests, to development.

- Increase agricultural productivity.

- Restore forests and landscapes.

- Reduce food loss and waste.

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3 years ago

We can reasonably model a 90-W incandescent lightbulb as a sphere 7.0cm in diameter. Typically, only about 5% of the energy goes

Ronch [10]

Answer:

292.3254055 W/m²

469.26267 V/m

$1.56421\times 10^{-6}\ T$

Explanation:

P = Power of bulb = 90 W

d = Diameter of bulb = 7 cm

r = Radius = $\frac{d}{2}=\frac{7}{2}=3.5\ cm$

$\epsilon_0$ = Permittivity of free space = $8.85\times 10^{-12}\ F/m$

c = Speed of light = $3\times 10^8\ m/s$

The intensity is given by

$I=\frac{P}{A}\\\Rightarrow I=\frac{90}{4\pi 0.035^2}\\\Rightarrow I=5846.50811\ W/m^2$

5% of this energy goes to the visible light so the intensity is

$I=0.05\times 5846.50811\\\Rightarrow I=292.3254055\ W/m^2$

The visible light intensity at the surface of the bulb is 292.3254055 W/m²

Energy density of the wave is

$u=\frac{1}{2}\epsilon_0E^2$

Energy density is also given by

$\frac{I}{c}=\frac{1}{2}\epsilon_0E^2\\\Rightarrow E=\sqrt{\frac{2I}{c\epsilon_0}}\\\Rightarrow E=\sqrt{\frac{2\times 292.3254055}{3\times 10^8\times 8.85\times 10^{-12}}}\\\Rightarrow E=469.26267\ V/m$

The amplitude of the electric field at this surface is 469.26267 V/m

Amplitude of a magnetic field is given by

$B=\frac{E}{c}\\\Rightarrow B=\frac{469.26267}{3\times 10^8}\\\Rightarrow B=1.56421\times 10^{-6}\ T$

The amplitude of the magnetic field at this surface is $1.56421\times 10^{-6}\ T$

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3 years ago

The Earth rotates and the moon revolves in the same direction.<br><br> True<br> False

tatyana61 [14]

The moon orbits the earth in the same direction as the earth, like if you had a ball on a string and you started spinning, the ball would spin the same direction.<span />

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3 years ago

Read 2 more answers

What is the wavelength of the third harmonic in a 4.5-m-long pipe that is closed at one end?

lisov135 [29]

Answer:

Wavelength of sound in the pipe is 6.0 m

Explanation:

As we know that closed pipe is given to us so here at open end it will form antinode while at closed end it will form Node

Here we know that in closed pipes on odd harmonics will exist

so here for third harmonic we have

$L = \frac{\lambda}{4} + \frac{\lambda}{2}$