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4 years ago

12

Mr. Hoffman, a science teacher, drove 10 miles to school from home in 20 minutes. He drove the 10 miles home in 30 min. His aver

age velocity was _____ m/s.

2 answers:

olga2289 [7]4 years ago

7 0

His average velocity for the day was 0. He ended where he started so his displacement was 0.

Andrews [41]4 years ago

4 0

zero.

Because he finished right where he started. his total displacement zero. therefore, his average velocity was also zero

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Answer:

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Okay then yes sorry that I must have gotten it wrong before.

Explanation:

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A diagnostic sonogram produces a picture of internal organs by passing ultrasound through the tissue. In one application, it is

miss Akunina [59]

Answer:

1) $\lambda = 11\times 10^{-4} m$

2) $2.51\times 10^9 Pa$

Explanation:

Given data:

speed of sound v = 1540 m/s

frequency f = 1.40 MHz = 1.40 \times 10^6 Hz

density $\rho = 1060 kg/m^3$

1) we know that

$v = f\lambda$

$\lambda = \frac[v}{f} = \frac{1540}{1.40\times 10^6}$

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2) we know that

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4 years ago

A 55-kg mountain climber, starting from rest, climbs a vertical distance of 701 m. At the top, she is again at rest. In the proc

aksik [14]

Answer:

7.75%

Explanation:

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height, h = 701 m

Qc = 4.5 x 10^6 J (heat exhaused by the body)

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W = 55 x 9.8 x 701

W = 377839 J

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e = 0.0774 = 7.75 %

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3 years ago

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Average velocity = displacement / time

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average velocity = 0 / 60 sec = zero

the average speed is calculated using total distance traveled.

average speed = distance / time

average speed = 120 meters / 60 sec = 2 m/s

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