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labwork [276]
3 years ago
10

An airplane flies 21 km in 30 minutes. What is its average speed in kilometers per hour?

Physics
2 answers:
Katena32 [7]3 years ago
8 0

Average speed = (distance covered) / (time to cover the distance)

Average speed = (21 km) / (1/2 hour)

Average speed = (21/0.5) (km/hour)

Average speed = 42 km/hr

A very slow airplane !  Maybe an ultralight, a motorized hang-glider, etc.

Citrus2011 [14]3 years ago
7 0
30 minutes is 1/2 of an hour.

So if you just multiplied 21×2, you would get you answer.
The answer is:
42 kilometers per hour
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5 0
3 years ago
A ray of light is incident on a flat surface of a block of polystyrene, with an index of refraction of 1.49, that is submerged i
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Answer:

21.5°

Explanation:

Given,

Refractive index of water, n₁ = 1.33

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Angle of refraction = 19.1°

Using Snell's law

n₁ sin θ₁ = n₂ sin θ₂

1.33 x sin θ₁ = 1.49 x sin 19.1°

sin θ₁ = 0.366

θ₁  = 21.5°

According to law of reflection angle of incidence is equal to angle of reflection.

Angle of reflection =  21.5°

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3 years ago
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B, gossiping is unproessional
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Which of the following is a harmful effect of oil spills? (A)Migration of large schools of fish (B)Changes in sea level (C)Plant
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B) 7.87 m/s

The gravitational pull is the rate of change of velocity which is the acceleration. Formula for acceleration is;
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Given:

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We're require to find the final velocity, at which the ball hit the ground with. Ignoring air resistance, keep in mind that the velocity of an object increases as it comes closer to the ground.

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5 0
3 years ago
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