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3 years ago

A ball dropped from a window strikes the ground 2.76 seconds later. How high is the window above the ground

Physics

1 answer:

sweet [91]3 years ago

7 0

Answer:

37.33m

Explanation:

Using the equation of motion

S = ut + 1/2gt^2

Time t = 2.76secs

g = 9.8m/s^2

S = 0 + 1/2(9.8)(2.76)^2

S = 4.9*7.6176

S = 37.33

Hence the window is 37.33m above the ground

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Blood flow rates in the umbilical cord can be found by measuring the Doppler shift of the ultrasound signal reflected by the red

lesya692 [45]

Answer:

fR = f(c + v)/c

Explanation:

The speed of a wave is its frequency x wavelenght. Therefore,

Frequency is speed of wave over the wavelength.

Since the source (ultrasound machine) is stationary, and the receiver red blood cell is moving towards it. The wavelenght of the wave sent out towards the observer is c/f

The speed of the reflected sound wave is (c + v), so that the reflected frequency fR is given by

fR = f(c + v)/c

5 0

4 years ago

Using a 679 nm wavelength laser, you form the diffraction pattern of a 1.1 mm wide slit on a screen. You measure on the screen t

sveta [45]

To solve the problem, apply the concepts related to constructive and destructive interference. For this purpose, we will start by defining the distance from the dark fringe from the central maximum in terms of the slit separation, the number of fringe the wavelength and the distance of the screen to the slit. Mathematically this is,

$y_n = \frac{(2n-1)\lambda D}{2d}$

$D = \frac{2dy_n}{(2n-1)\lambda}$

Here,

d = Slit separation

n = Number of fringe

$y_n$ = Distance of the dark fringe from the central maximum

D = Distance of the screen to the slit

$\lambda$ = Wavelength

Our values are given as,

$\lambda = 679nm = 679*10^{-9}m$

$d = 1.1mm = 1.1*10^{-3}m$

$y_{14} = 8.01cm = 8.01*10^{-2} m$

$n = 14$

Replacing,

$D = \frac{2(1.1*10^{-3})(8.01*10^{-2})}{(2(14)-1)(679*10^{-9})}$

$D = 9.61m$

Therefore the screen is located from the slit to 9.61m

7 0

3 years ago

Use the equation d=m/v. If a rock has a density of 2g/cm^3 and a volume of 8cm^3, what is the mass?

Ray Of Light [21]

Answer:

The mass is 16 [g]

Explanation:

We have to remember the formula that defines density, which mentions that the density is equal to mass divided by the volume.

$Density = mass / volume\\where:\\density = 2[\frac{g}{cm^{3} } ]\\Volume = 8 [cm^{3}]$

Now we clear the mass:

$mass= density*volume\\mass = 2[\frac{g}{cm^{3} }]*8[cm^{3} ]\\mass = 16 [g]$

8 0

3 years ago

Two loudspeakers emit sound waves along the x-axis. A listener in front of both speakers hears a maximum sound intensity when sp

yKpoI14uk [10]

Answer

given,

difference between the two consecutive maximum

λ = 0.870 - 0.540

λ = 0.33 m

speed of sound = 340 m/s

b) frequency of the sound

v = f x λ

340 = f x 0.33

$f =\dfrac{340}{0.33}$

f = 1030.3 Hz

a) phase difference

the expression of phase difference is given by

$\phi = \dfrac{2\pi}{\lambda}\ \delta$

$\delta = \Delta x - \lambda$

$\delta = 0.540 - 0.33$

$\delta = 0.21\ m$

now,

$\phi = \dfrac{2\pi}{\lambda}\ \times 0.21$

$\phi = \dfrac{2\pi}{0.33}\ \times 0.21$

$\phi = 3.99 rad$

8 0

3 years ago

How does the earth orbit the sun?

scoray [572]

Answer:

The Sun's gravity pulls on the planets, just as Earth's gravity pulls down anything that is not held up by some other force and keeps you and me on the ground.

Explanation:

Hope that helps

6 0

3 years ago