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spin [16.1K]
3 years ago
14

A lightbulb has an effciency of 8.2%. How much light energy (not heat energy) is generated by the bulb every second if the buld

has pwer of 21w?
Physics
1 answer:
telo118 [61]3 years ago
8 0
It really depends on what the bulb is being used for, since efficiency means how much of the output is USEFUL.
If the bulb is being used for light in a dark room, then it produces (8.2% x 21W) = 1.72 joules per second of light energy.
If the bulb is being used to keep a hamster cage or a fish tank warm, then the 8.2% is the useful part, and the light is the other (91.8% x 21W) = 19.28 joules per second.
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Help me with this question Please
zysi [14]

Answer:

W has the lowest density and Y has the greatest density

Explanation:

Density of W = mass/volume = 11/24 = 0.45

Density of X = mass/volume = 11/12 = 0.91

Density of Y = m/v = 5.5/4 = 1.375

Density of Z = m/v = 5.5/11 = 0.5

From these we can find the answer......

Hope this answer is useful......

3 0
3 years ago
An infinitely long cylindrical insulating shell of inner radius a and outer radius b has a uniform volume charge density p. Dete
xenn [34]

Answer: The electric field is: a) r<a , E0=; b) a<r<b E=ρ (r-a)/εo;

c) r>b E=ρ b (b-a)/r*εo

Explanation: In order to solve this problem we have to use the Gaussian law in diffrengios regions.

As we know,

∫E.dr= Qinside/εo

For r<a --->Qinside=0 then E=0

for a<r<b er have

E*2π*r*L= Q inside/εo       in this case Qinside= ρ.Vol=ρ*2*π*r*(r-a)*L

E*2π*r*L =ρ*2*π*r* (r-a)*L/εo

E=ρ*(r-a)/εo

Finally for r>b

E*2π*r*L =ρ*2*π*b* (b-a)*L/εo

E=ρ*b* (b-a)*/r*εo

3 0
2 years ago
Two large, flat, horizontally oriented plates are parallel to each other, a distance d apart. Half-way between the two plates th
fgiga [73]

Answer:

Explanation:

Let the potential difference between the plate is V . Then in the first case

Electric field E between plate

E₁ = V / d

where d is separation between plate

When the plate separation becomes d / 2

Electric field E between plate

E₂ = V / d /2

= 2 V / d =2E₁

Or twice the earlier field

5 0
3 years ago
A soda has a volume of 560 mL and a density of 3.2 g/mL. What is the mass?
kolbaska11 [484]
The correct answer is: 1792g or 1800g.

(When you round it)
8 0
3 years ago
QUESTION 36
mel-nik [20]

Answer:

Explanation:

m = ρV = 1.03( 1000 kg/m³)(π(2² m²)(3.0 m)) = 12360π kg

m ≈ 38,830 kg

5 0
3 years ago
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