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S_A_V [24]
3 years ago
5

Our ancestors are our guides?​

Physics
1 answer:
aleksandr82 [10.1K]3 years ago
4 0

Answer:

yes

Explanation:

we can clearly say that our ancestor are our guide.

Because of they give us different knowledge about evolution of life and etc.

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In an electron microscope, electrons are accelerated to great velocities. Calculate the wavelength of an electron traveling with
Diano4ka-milaya [45]

Answer:

Wavelength, \lambda=1.04\times 10^{-13}\ m

Explanation:

It is given that,

Velocity of an electron, v=7\times 10^6\ m/s

Mass of an electron, m=9.1\times 10^{-28}\ kg

We need to find the wavelength of an electron. It can be calculated using the De- Broglie wavelength as :

\lambda=\dfrac{h}{mv}

\lambda=\dfrac{6.63\times 10^{-34}}{9.1\times 10^{-28}\times 7\times 10^6}

\lambda=1.04\times 10^{-13}\ m

So, the wavelength of an electron is 1.04\times 10^{-13}\ m. Hence, this is the required solution.

7 0
3 years ago
A watermelon is blown into three pieces by a large firecracker. Two pieces of equal mass m fly away perpendicular to one another
laiz [17]

Answer

given,

watermelon blown into three pieces

two pieces of mass m

both pieces speed = v = 31 m/s

mass of third piece = 3 m

using conservation of mass

0 = m V \hat{i} + m V \hat{j} + (3\ m)V_3

V_3 = \dfrac{V}{3}(-\hat{i}-\hat{j})

V_3 = \dfrac{V}{3}\sqrt{1^2+1^2}

V_3 = \dfrac{V}{3}\sqrt{2}

velocity of third component

V_3 = \dfrac{31}{3}\sqrt{2}

V_3 = 14.61\ m/s

angle

\theta = tan^{-1}(\dfrac{-1}{-1})

\theta = tan^{-1}(1)

\theta = 45^0

5 0
4 years ago
A circuit is shown in the picture above. The chemical energy in the battery is used to light up the light bulb on the other end.
Ainat [17]
To be honest, the picture is so far above that I can't see it at all.
But reading the information in the question's statement, I'd say
the blank should be filled in so that it says:

<span>   The chemical energy in the battery is used to light up the light bulb
   on the other end. Chemical energy in the battery is transformed into
   electrical energy which runs through the circuit wire. (A)</span>
8 0
4 years ago
Read 2 more answers
"On a movie set, an alien spacecraft is to be lifted to a height of 32.0 m for use in a scene. The 260.0-kg spacecraft is attach
Lisa [10]

Answer:

<em>The time interval required to lift the spacecraft to this specified height is 123.94 seconds</em>

Explanation:

Height through which the spacecraft is to be lifted = 32.0 m

Mass of the spacecraft = 260.0 kg

Four crew member each pull with a power of 135 W

18.0% of the mechanical energy is lost to friction.

work done in this situation is proportional to the mechanical energy used to move the spacecraft up

work done = (weight of spacecraft) x (the height through which it is lifted)

but the weight of spacecraft = mg

where m is the mass,

and g is acceleration due to gravity 9.81 m/s

weight of spacecraft = 260 x 9.81 = 2550.6 N

work done on the space craft = weight x height

==> work = 2550.6 x 32 = 81619.2 J

this is equal to the mechanical energy delivered to the system

18.0% of this mechanical energy delivered to the pulley is lost to friction.

this means that

0.18 x 81619.2  = <em>14691.456 J  </em> is lost to friction.

Total useful mechanical energy =  81619.2 J - 14691.456 J = 66927.74<em> J</em>

Total power delivered by the crew to do this work = 135 x 4 = 540 W

But we know tat power is the rate at which work is done i.e

P = \frac{w}{t}

where p is the power

where w is the useful work done

t is the time taken to do this work

imputing values, we'll have

540 = 66927.74/t

t = 66927.74/540

time taken t = <em>123.94 seconds</em>

8 0
3 years ago
Which wave lies adjacent to the low frequency portion of the visible spectrum
fgiga [73]

Answer: b. infrared

Explanation:

The visible light with the smaller frequency is associated with the color red.

While the blue is the one with the larger frequency.

Now, as the name says, infrared waves are the ones with a frequency just below the one of the red visible light.

Where the frequency of the red light is something around (4.3*10^14 Hz)

and the frequency of the infrared waves is in the range between (10^12 Hz and 10^14 Hz)

Then the correct option is b, infrared.

8 0
3 years ago
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