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faltersainse [42]
3 years ago
12

A quantum of electromagnetic radiation has an energy of 2.0 kev. what is its frequency? planck's constant is 6.63 × 10−34 j · s.

answer in units of hz.
Physics
1 answer:
xxMikexx [17]3 years ago
8 0
A quantum of electromagnetic radiation is called photon, and the energy of a photon is given by
E=hf (1)
where h is the Planck constant and f is the frequency of the photon.

In this problem, the photon energy is
E=2.0 keV=2.0 \cdot 10^3 eV=3.2 \cdot 10^{-16} J
If we re-arrange equation (1), we can find the energy of the photon:
f= \frac{E}{h}= \frac{3.2 \cdot 10^{-16} J}{6.6 \cdot 10^{-34} Js}=4.8\cdot 10^{17} Hz
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Aliun [14]
In empty space probably means, there is no force on the ball.

(This assumption is not quite correct since there is still the force of gravity between the ball and the astronaut, but this force is very very small and can be neglected.)

Assuming there is no force on the ball, Newtown's 1st law says: When viewed in an internal frame of reference, an object either remains at rest or continues to move at a constant velocity, unless acted upon by a force.
 
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3 0
3 years ago
Helpppp!!!ASAP!! THANK YOUUUU!
mario62 [17]

Answer:

F = 9.675Hz

Explanation:

pls for certain reasons let us make

  • wavelength = $
  • frequency = F
  • V = velocity

3 loops : 6$/4 = L

6$/4 = 2

$ = 4/3 = 1.333

V = F x $

F = V/$

F = 12.9/1.333 = 9.675Hz

F = 9.675Hz

4 0
2 years ago
A student lifts a 90 pound (lb) ball 4 feet (ft) in 5 seconds (s). How many joules of work has the student completed?
scZoUnD [109]

Wending your way through this question and the list of choices
is like running through a corn-maze on a moonless night with
your eyes closed.

Work = (force) x (distance)

Keeping with the units used In the question ...

       Work = (90 pounds) x (4 feet)  =  360 foot-pounds .

If you want the work expressed in joules, then you need to convert
pounds and feet to newtons and meters.

           (90 pounds) x (4.448 newtons/pound) =  400.32 Newtons

               (4 feet) x (1 meter / 3.28084 feet)  =  1.219 meters

Work = (force) x (distance)

          = (400.32 newtons) x (1.219 meters) = 488.1 joules .

7 0
2 years ago
How much net force is needed to accelerate a 20kg mass at 2.5 m/s2?
Ksenya-84 [330]

Answer:

\boxed{Force \: needed = 50 \: N}

Given:

Mass = 20 kg

Acceleration = 2.5 m/s²

Explanation:

Force = mass × acceleration

= 20 × 2.5

= 50 kg m/s² or 50 N

8 0
2 years ago
Which of the mixtures in figure 1 is a solution?
adelina 88 [10]

whats the example? That all yu should look it up on internet.

6 0
2 years ago
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