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3 years ago

Work, Power, and Energy

Physics

1 answer:

leva [86]3 years ago

3 0

Answer:

383.2

Explanation:

W=m×g(9.8)×(change in height)

=3×9.8× (45-32)

=3×9.8×13

=383.2

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Does Earth´s magnetic field move?

AlekseyPX

Answer:

Yes it does.

Explanation:

"The North Magnetic Pole moves over time due to magnetic changes in Earth's core. " - Wikipedia.

It does move around as the magnetic north does.

6 0

3 years ago

Which quantities are scalars?

Fofino [41]

Answer:

A and B

Explanation:

Because both of them have only magnitude not direction.

7 0

3 years ago

Read 2 more answers

Suppose a plot of inverse wavelength vs frequency has slope equal to 0.119, what is the speed of sound traveling in the tube to

strojnjashka [21]

Answer:

8.40 m/s

Explanation:

Slope of the plot is 0.119

Slope of a plot is given by the change in y direction divided by the change in x direction

Here, the y axis represents inverse wavelength and the x axis represents frequency.

f = Frequency (Hz, assumed)

v = Phase velocity (m/s, assumed)

λ = Wavelength (m, assumed)

So, slope

$m=\frac{\frac{1}{\lambda}}{f}$

Now,

$\lambda=\frac{v}{f}\\\Rightarrow \lambda^{-1}=\frac{f}{v}$

$\\\Rightarrow m=\frac{\frac{f}{v}}{f}\\\Rightarrow 0.119=\frac{1}{v}\\\Rightarrow v=\frac{1}{0.119}\\\Rightarrow v=8.40\ m/s$

The speed of sound travelling in the tube is 8.40 m/s

5 0

3 years ago

The gravitational force,F, on a rocket at a distance,r, from the center of the earth isgiven byF=kr2wherek= 1013N·km2. (Newton·k

Brrunno [24]

Answer:

The gravitational force changing velocity is

$\frac{dF}{dt}=-8\frac{N}{s}$

Explanation:

The expression for the gravitational force is

$F=\frac{k}{r^{2}}\\\\k=10x10^{13} N*km^{2}\\\\r=10x10^{4} km\\\\V=0.4 \frac{km}{s}$

Differentiate the above equation

$\frac{dF}{dt}=\frac{k}{r^{2}}\\\frac{dF}{dt}=k*r^{-2}\\\frac{dF}{dt}=-2*k*r^{-3} \frac{dr}{dt}\\\frac{dF}{dt}=\frac{-2k}{r^{3}}\frac{dr}{dt}$

The velocity is the distance in at time so

$V=\frac{dr}{dt}=0.4 \frac{km}{s}$

$\frac{dF}{dt}=\frac{-2*k}{r^{3}}*0.4\\\frac{dF}{dt}=\frac{-8*10x^{13}N*km^{2} }{(10x10^{4}) ^{3}} \\\frac{dF}{dt}=\frac{-8x10^{12} }{1x10^{12}}$

$\frac{dF}{dt}=-8\frac{N}{s}$

8 0

3 years ago

One cereal bar has a mass of 37 g. What is the mass of 6 cereal bars? Is that more than or less than 1 kg? Explain your answer.

GuDViN [60]

The mass is 222g. No, it is less than 1kg. There are 1000 grams in a kilogram so it would be 0.222kg. Hope this Helps :D

7 0

3 years ago