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3 years ago

Which of the following is an example of a speed? O A. -5 m/s2 west O B. 2m/s C. 2 m/s east O D. 3 m/s south

Physics

1 answer:

andrey2020 [161]3 years ago

4 0

B is a speed.

A is an acceleration.

C and D are velocities.

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Find average speed when time= 27s and total distance is 94m

Slav-nsk [51]

3.4814815 (or 3 13/27) m/s

speed = distance/time
3.4814815 (or 3 13/27) = 94/27

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2 years ago

Water is discharged from a pipeline at a velocity v (in ft/sec) given by v = 1306p(1/2), where p is the pressure (in psi). If th

shepuryov [24]

Answer:

$a=38.5 ft/sec^{2}$

Explanation:

Note that acceleration is the rate change of velocity i.e

$acceleration=\frac{change in velocity}{change in time}\\a=\frac{dv}{dt} \\$ .

Since the velocity is giving as a variable dependent on the pressure, we have to differentiate implicitly both side with respect to time,i.e

$\frac{dv}{dt}=1306*(1/2)p^{-1/2}\frac{dp}{dt} \\$

if we substitute value for the pressure as giving in the question and also since the rate change of pressure is 0.354psi/sec, we have

$a=653*0.1667*0.354\\$

$a=\frac{dv}{dt}=653(36)^{-1/2}*0.354\\ a=38.5 ft/sec^{2}$

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2 years ago

What molecule determines the characteristics a child will inherit from its parents?

Korvikt [17]

Answer:

A molecule called DNA (deoxyribonucleic acid) is passed from adult organisms to their offspring during reproduction. This molecule containsthe instructions for an organism to develop, grow, survive and reproduce.

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2 years ago

A. How long does it take light to travel through a 3.0-mm-thick piece of window glass?

hodyreva [135]

Answer:

a) $1.517\times10^{-11}$ s

b) 3.41 mm

Explanation:

We take the speed of light, c = $3.0\times10^8$ m/s and the refractive index of glass as 1.517.

Speed = distance/time

Time = distance/speed

Refractive index, n = speed of light in vacuum / speed of light in medium

$n=\dfrac{c}{s}$

$s=\dfrac{c}{n}$

$t=\dfrac{d}{c/n}$

$t=\dfrac{dn}{c}$

$t=\dfrac{3\times10^{-3}\times1.517}{3.0\times10^8}$

$t=1.517\times10^{-11}$

We take the refractive index of water as 1.333.

Speed in water = speed in vacuum / refractive index of water

Distance = speed * time

$d=s\times t$

$d=\dfrac{c}{n_w}\times \dfrac{3\times10^{-3}\times1.517}{c}$

$d=\dfrac{3\times10^{-3}\times 1.517}{1.333}$

d = 3.41 mm

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3 years ago

No sistema representado abaixo, a massa do bloco A é igual a 2 kg, a do bloco B é igual a 8 kg.

blagie [28]

Answer:

Explanation:19,2 or 0/4 or 5 or 40,4

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2 years ago