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2 years ago

9

Calculate the height of a cliff if it takes 2.35 s for a rock to hit the ground when it is thrown straight up from the cliff wit

h an initial velocity of 8.00

1 answer:

pantera1 [17]2 years ago

7 0

Answer:

height of a cliff is 45.86 m

Explanation:

u=8 m/s

t=2.35 s

the height of the cliff is

$S=ut+\frac{1}{2} at^2\\S=8\times2.35+\frac{1}{2} \times 9.8 \times 2.35^2\\S=45.86 m$

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Two long straight wires are parallel and 8.6 cm apart. They are to carry equal currents such that the magnetic field at a point

Neko [114]

Answer:

(a) The current should be in opposite direction

(b) The current needed is 39.8 A

Explanation:

Part (a)

Based, on right hand rule, the current should be in opposite direction

Part (b)

given;

strength of magnetic field, B = 370 µT

distance between the two parallel wires, d = 8.6 cm

$B = \frac{\mu_oI}{2\pi R}$

At the center, the magnetic field strength is twice

$B_c = 2(\frac{\mu_oI}{2\pi R}) =\frac{ \mu_oI}{\pi R}$

R = d/2 = 8.6/2 = 4.3 cm = 0.043 m

$B_c = \frac{ \mu_oI}{\pi R}\\\\I = \frac{B_c\pi R}{\mu_o} = \frac{370 *10^{-6}* \pi *0.043}{4\pi *10^{-7}}\\\\I = 39.8 \ A$

Therefore, current needed is 39.8 A

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2 years ago

The labeled images each represent the wave patterns found in the electromagnetic wave spectrum. which of these images are correc

Phantasy [73]

Energy E of EM radiation is given by the equation E=hf, where h is Planck's constant and f is frequency. It means energy E and frequency f are proportional so as we increase the frequency, energy also increases. Also, the relationship between the wavelength and frequency is c=λ*f where λ is the wavelength and f is frequency and c is the speed of light. This tells us the wavelength and frequency are inversely proportional. So as we increase the frequency the wavelength is getting smaller. So as we go from left to right the frequency increases, energy also increases and the wavelength is decreasing. Or, on the left side we should have low frequency, low radiant energy, and long wavelength. On the right side we should have high frequency, high radiant energy and low wavelength. That is the third graph.

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2 years ago

9. a. Determine the mass of a football which has a weight of 0.80 N on a planet where the gravitational field strength is 2 N/kg

krek1111 [17]

Answer:

m = 0.4 [kg]

Explanation:

Weight is considered as a force and this is equal to the product of mass by gravitational acceleration.

$W=m*g\\$

where:

W = weight = 0.8 [N]

m = mass [kg]

g = gravity acceleration 2[N/kg]

Therefore:

$m=W/g\\m = .8/2\\m = 0.4 [kg]$

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2 years ago

What is the work behind these answers?

Sati [7]

I think you need to solve them

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2 years ago

We see a full moon by reflected sunlight. how much earlier did the light that enters our eye leave the sun

galina1969 [7]

We know that the source of light in the universe is the Sun. Hence, the light we see as moonlight travels from the Sun's surface, to the moon, then to Earth. So, before being able to solve this problem, we have to know the distance between the Sun and the moon, and the distance between the moon and Earth. In literature, these values are 3.8×10⁵ km (Sun to moon) and 384,400 km (moon to Earth). Knowing that the speed of light is 300,000 km per second, then the total time would be

Time = distance/speed
Time = (3.8×10⁵ km + 384,400 km)/300,000 km/s
Time = 2.548 seconds

Thus, it only takes 2.548 for the light from the Sun to reach to the Earth as perceived to be what we call moonlight.

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2 years ago