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tiny-mole [99]
3 years ago
15

How many nanoseconds does it take light to travel 2.50 feet in a vacuum

Physics
1 answer:
Monica [59]3 years ago
5 0
A handy-dandy "rule of thumb" that I and many other engineers
have been using for years is:       

                                     1 nanosecond ===> 1 foot. 

Let's figure it out and see whether that's even close:

Speed of light in vacuum = 299,792,458 meters per second.

         (299,792,458 m/s) x ( 1 sec / 10⁹ nanosec) x (3.28084 ft/meter)

     =  (299,792,458 x 1 x 3.28084 x 10⁻⁹)  ft/nanosec

     =            0.983571  ft/nanosec  .

       That's  1.64%  less than  1.000000 .
       The engineer's handy-dandy rule of thumb is valid.

2.5 feet would take

           (2.5  x  0.983571 sec)  =   2.45893 nanoseconds
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5 0
3 years ago
Read 2 more answers
Not in book
umka2103 [35]

Answer:

x=2.4365\ m

and

x=-1.4365\ m

Explanation:

Given:

  • first charge, q_1=5\times 10^{-3}\ C
  • second charge, q_2=3\times 10^{-3}\ C
  • position of first charge, x_1=-2\ m
  • position of second charge, x_2=-1\ m

Now since there are only 2 charges and of the same sign so they repel each other. This repulsion will be zero at some point on the line joining the charges.

<u>Now, according to the condition, electric field will be zero where the effects of field due to both the charges is equal.</u>

E_1=E_2

  • since first charge is greater than the second charge so we may get a point to the right of the second charge and the distance between the two charges is 1 meter.

\frac{1}{4\pi.\epsilon_0} \frac{q_1}{(r+1)^2} =\frac{1}{4\pi.\epsilon_0} \frac{q_2}{(r)^2}

\frac{5\times 10^{-3}}{(r+1)^2} = \frac{3\times 10^{-3}}{(r)^2}

3(r^2+1+2r)=5r^2

2r^2-6r-3=0

r=3.4365 \&\ r=-0.4365

Since we have assumed that the we may get a point to the right of second charge so we calculate with respect to the origin.

x=-1+3.4365=2.4365\ m

and

x=-1-0.4365=-1.4365\ m

6 0
3 years ago
A kettle is rated at 1 kW, 220 V. Calculate the working resistance of the kettle.
Anna [14]

Explanation:

Power of electric kettle, P = 1 kW

Voltage, V = 220 V

(a) Electric power is given by the formula as follows :

P=\dfrac{V^2}{R}

R is resistance

R=\dfrac{V^2}{P}\\\\R=\dfrac{(220)^2}{10^3}\\\\R=48.4\ \Omega

(b) When connected to a 220 V supply, it takes 3 minutes for the water in the kettle to reach boiling point.

Energy supplied is given by :

E=P\times t

P is power, P=\dfrac{V^2}{R}

E=\dfrac{V^2}{R}t\\\\E=\dfrac{(220)^2}{48.4}\times 180\\\\E=180000\ J\\\\E=180\ kJ

5 0
3 years ago
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Answer:

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An object that looks white when exposed to sunlight reflects all colors of light. What
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