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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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This is a change in the position of a body with respect to time relative to a reference point.
dusya [7]

Answer: MOTION

Explanation:

motion is defined as the displacement of an object with respect to time relative to a stationary object (reference point). A good example of an object that can serve as a reference point includes: a tree or a building. The movement of a body at constant speed towards a particular direction at regular intervals of time can be determined and it's called uniform motion.

There are different types of motion, these includes: simple harmonic motion,

linear motion,

circular motion,

Brownian motion,

Rotatory motion

5 0
3 years ago
Read 2 more answers
A small boat sailed straight north out of a harbor in strong east wind (blowing from west to east). After sailing for 120 minute
Amiraneli [1.4K]

it can be said that  the speed of the east wind is

v=0.3608m/s

From the question we are told

A small boat sailed <u>straight </u>north out of a harbor in <em>strong </em>east wind (blowing from west to east).

After sailing for 120 minutes, it ended up hitting a buoy 60^\circ60 ∘ to the north-east of the harbor. If the straight-line distance between the buoy and the harbor is 3 km,

  • what is the speed of the east wind?.

<h3> the speed of the east wind</h3>

Generally the equation for the distance  is mathematically given as

BA=3000sin60

BA=2598.07m

Therefore

the speed of the east wind

V_w=\frac{BA}{120*60}\\\\V_w=\frac{2598.07}{120*60}

v=0.3608

For more information on this visit

brainly.com/question/22568180

7 0
2 years ago
A transformer has input voltage and current of 12 V and 4 A
Advocard [28]

Explanation:

It is given that,

Input voltage, V_i=12\ V

Input current, I_i=4\ A

Output current, I_o=0.8\ A

Number of turns in the secondary side of transformer, N_s=1177

We need to find the number of turns in the primary side of the transformer. The current to the number of turns in the input and output is given by :

\dfrac{N_s}{N_p}=\dfrac{I_p}{I_s}

Substituting all the above values

So,

N_p=\dfrac{N_sI_s}{I_p}\\\\N_p=\dfrac{1177\times 4}{0.8}\\\\N_p=5885

So, the number of turns in primary side of the transformer is 5885.

4 0
3 years ago
Define fundamental unit ? write its two example. ​
stealth61 [152]

the International System of Units, the fundamental units are: The meter (symbol: m), used to measure length. The kilogram (symbol: kg), used to measure mass. The second (symbol: s), used to measure time. The ampere (symbol: A), used to measure electric current.

8 0
3 years ago
When a object is at rest, what is it’s speed??
nadya68 [22]

Answer:

0   (there is no speed)

Explanation:

If an object is at rest, it is not moving, and it doesn't have a speed, so the speed is zero.

3 0
3 years ago
Read 2 more answers
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