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3 years ago

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If the diameter of each of a car's wheels is 0.4 meters, approximately, what was the average speed of the car for its three-hour

trip in which each wheel made 100,000 revolutions?

2 answers:

Reptile [31]3 years ago

8 0

Answer:

42 km/h was the average speed of the car for its three-hour trip.

Explanation:

Diameter of the car wheel = d = 0.4 m

Radius of the car wheel = r = 0.5 d = 0.5 × 0.4 m =0.2 m

Distance covered in 1 complete revolution = $2\pi r$

Distance covered in 100,000 complete revolution,D = $2\pi r\times 100,000$

$D=2\times 3.14\times 0.2 m\times 100,000=125,663.71 m$

1 m = 0.001 km

125,663.71 m = 125,663.71 × 0.001 km = 125.66371 km

Time taken to complete 100,000 revolution by a wheel = t = 3 hours

Speed of car : S

$S=\frac{125.66371 km}{3hours}=41.89 km/h\approx 42 km/h$

42 km/h was the average speed of the car for its three-hour trip.

bogdanovich [222]3 years ago

3 0

Answer:

Explanation:

diameter = 0.4 m

Radius, r = 0.2 m

Time, t = 3 hour

number of revolutions, = 100,000

Distance traveled in one revolution = 2 x π x r = 2 x 3.14 x 0.2 = 1.256 m

Total distance in 100,000 revolutions,

d = 100,000 x 1.256 = 125600 m

d = 125.6 km

Average speed = distance / time

Average speed = 125.6 / 3 = 41.87 km/h

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An example of this is when a person is collecting raindrops with a bucket and with a cup. Since the bucket has a bigger area than the cup, it will collect more raindrops by unit of time. In this scenario the raindrops represent the photons.

To determine the light collecting area of each telescope, equation 2 will be replaced in equation 1.

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$A = \pi (\frac{8.3m}{2})^{2}$

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Large binocular telescope, Keck 1 telescope, Hobby-Ebberly telescope, Subaru telescope, Gemini North telescope, Magellan 2 telescope.

<em>Key term:</em>

<em>Photons: particles that constitute light. </em>

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