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andreyandreev [35.5K]
3 years ago
10

what is the percent efficiency of a light bulb that emits 14 joules of light for every 60 joules of electric energy thst enters

it?
Physics
1 answer:
jasenka [17]3 years ago
5 0
If you're using the bulb as a source of light, then it's. 14/60 = 23.3% efficient.
If you're using it to heat a bird nest or a hamster cage, then it's. 46/60 = 76.7% efficient !
It just depends on your point of view, and what you consider 'useful' output.
You might be interested in
Suppose an electron and a proton move at the same speed. which particle has a longer de broglie wavelength? suppose an electron
BARSIC [14]
When both particles, the electron and the proton move at the same speed, they may have differences with their de Broglie wavelength, the particle that would have a longer wavelength would be the proton since the wavelength is in direct proportionality with the mass of the particle.
6 0
3 years ago
I need help with this please
Firdavs [7]
C is the answer to the question
6 0
3 years ago
A block on a horizontal frictionless plane is attached to a spring, as shown below. The block oscillates along the x-axis with s
AleksandrR [38]

The question is about unclear since no picture provided. But from the question, it could be guessed that the box is moving back and forth on the frictionless plane at the amplitude of A in simple harmonic motion.

Answer:

D. At x=0, it's acceleration is at a maximum

Explanation:

As the box move forward, it reaches point A and than move backward. Theoretically, the box will move backwards, through its origin, to point -A and then going forward.

Point A is the maximum displacement of the box in this case. At this point, the box instantaneously stop to go backward. Therefore the velocity at that moment is zero.

From point -A, the box travel forward and keep building up speed due to the release in potential energy of the spring. And at point x=0, the velocity become maximum. After point x=0, the velocity of the box slows down due to the conversion of kinetic energy to potential energy of the spring. And as it reaches point A, it reaches zero velocity.

The same can be said as the box travels backward from point A to -A

8 0
4 years ago
WILL GIVE BRAINLIEST!!!!!!!!!!!!!!!!!!
faust18 [17]

Answer:

9)a

10) I think true

11)b

Explanation:

9)a. because it's told that the car is slowing down, the sum of the forces that are towards left, should be more than the ones that are towards right. if the car was gaining speed, "b" would have been correct. and if it was told that the car is moving without a change in the speed, "c" would have been correct.

10) if a moving object has a change of speed or direction, it would have an acceleration. now if a moving object experiences an unbalanced force, it'd either slow down, gain speed or change direction, and in all of the three possibilities it'd have an acceleration.

11) upward and downward forces are equal, and the sum of them would be 0N(because they have opposite directions). so they negate each other.

and the rightward force is 5N more than the leftward force. so the Net Force would be 5N.

-30+30-10+15=5N

if it is unclear or you need more explanation, ask freely.

8 0
3 years ago
A proton moving at 8.00 106 m/s through a magnetic field of magnitude 1.72 T experiences a magnetic force of magnitude 7.20 10-1
gladu [14]

Answer:

19.1 deg

Explanation:

v = speed of the proton = 8 x 10⁶ m/s

B = magnitude of the magnetic field = 1.72 T

q = magnitude of charge on the proton = 1.6 x 10⁻¹⁹ C

F = magnitude of magnetic force on the proton = 7.20 x 10⁻¹³ N

θ = Angle between proton's velocity and magnetic field

magnitude of magnetic force on the proton is given as

F = q v B Sinθ

7.20 x 10⁻¹³ = (1.6 x 10⁻¹⁹) (8 x 10⁶) (1.72) Sinθ

Sinθ = 0.327

θ = 19.1 deg

4 0
3 years ago
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