1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Feliz [49]
3 years ago
13

(II) You buy a 75-W lightbulb in Europe, where electricity is delivered at 240 V. If you use the bulb in the United States at 12

0 V (assume its resistance does not change), how bright will it be relative to 75-W 120-V bulbs? [Hint: Assume roughly that brightness is proportional to power consumed.]
Physics
1 answer:
Elodia [21]3 years ago
4 0

Answer:

Explanation:

You are looking for the resistance to start with

W = E * E/R

75 = 240 * 240 / R

75 * R = 240 * 240

R = 240 * 240 / 75

R = 57600 / 75

R = 768

Now let's see what happens when you try putting this into 110

W = E^2 / R

W = 120^2 / 768

W = 18.75

So the wattage is rated at 75. 18.75 is a far cry from that. I think they intend you to set up a ratio of

18.75 / 75 = 0.25

This is the long sure way of solving it. The quick way is to realize that the voltage is the only thing that is going to change. 120 * 120 / (240 * 240) = 1/2*1/2 = 1/4 = 0.25

You might be interested in
You are watching an archery tournament when you start wondering how fast an arrow is shot from the bow. Remembering your physics
lianna [129]
<h2>Answer:</h2>

<em><u>Velocity of throwing arrow = 43.13 m/s.</u></em>

<h2>Explanation:</h2>

In the question,

Let us say the height from which the arrow was shot = h

Distance traveled by the arrow in horizontal = 61 m

Angle made by the arrow with the ground = 2°

So,

From the <u>equations of the motion</u>,

61 =u.t\\t=\frac{61}{u}

Now,

Also,

Finally, the angle made is 2 degrees with the horizontal.

So,

Final horizontal velocity = v.cos20°

Final vertical velocity = v.sin20°

Now,

u = v.cos20° (No acceleration in horizontal)

Also,

v=u+at\\vsin20=0+9.8(t)\\t=\frac{v.sin20}{9.8}

So,

We can say that,

\frac{v.sin20}{9.8}=\frac{61}{v.cos20}\\v^{2}.sin20.cos20=597.8\\v^{2}=1860.56\\v=43.13\,m/s

<em><u>Therefore, the velocity with which the arrow was shot by the archer is 43.13 m/s.</u></em>

5 0
3 years ago
What is a fact about incline planes?
SVETLANKA909090 [29]
They are incline hope this helps!
8 0
3 years ago
A major contemporary learning view of personality which holds that personality traits result from a
DIA [1.3K]

Answer:

21

Explanation:

21 is x because 211211 1 1 1 1  1aghh

3 0
3 years ago
Read 2 more answers
What happens when calcium reacts with chlorine?
larisa86 [58]

Answer:

Calcium chloride in an ionic compound. The calcium atom loses two electrons, and each chlorine atom gains one electron, to form a full outer shell of electrons.

5 0
3 years ago
Thermal equilibrium is reached when______________.
Art [367]
<span>two objects in contact with each other are the same temperature</span>
4 0
3 years ago
Read 2 more answers
Other questions:
  • Which candidate won an election that was ultimately decided by the supreme court
    15·1 answer
  • How does Connecticut energy affect the stopping distance of a vehicle traveling at 30 mph compared to the same vehicle traveling
    6·1 answer
  • How could two waves on a rope interfere so that the rope did not move at all.
    11·1 answer
  • Why is it harder to hear someone through a wall?
    11·1 answer
  • If f3=0 and f1=12n, what does the magnitude of f? 2 have to be for there to be rotational equilibrium? answer numerically in new
    15·1 answer
  • LOOK AT ATTACHMENT AND ANSWER QUESTION!
    7·2 answers
  • Electric current passing through a human body can be dangerous, even fatal, depending on the amount of current, the duration of
    9·1 answer
  • I can't figure out what the third number I need is in this question a car traveling at +20 m/s applies the brakes and stops in 6
    15·1 answer
  • a ball is rolled uphill a distance of 3 meters before it slows,stops,and begins to roll back. the ball rolls downhill 6 meters b
    13·1 answer
  • A car which is traveling at a velocity of 1.6 m/s undergoes an acceleration of 9.2 m/s over a distance of 540 m. How fast is it
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!