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2 years ago

The efficiency of a device such as a lamp can be calculated using this equation:

Physics

2 answers:

loris [4]2 years ago

6 0

efficiency = (useful energy transferred ÷ energy supplied) × 100

It's easy to use this formula, but we have to know both the useful energy and the energy supplied. The drawing doesn't tell us the useful energy, so we have to find a clever way to figure it out. I see two ways to do it:

Way #1:

We all know about the law of conservation of energy. So we know that the total energy coming out must be 250J, because that's how much energy is going in. The wasted energy is 75J, so the rest of the 250J must be the useful energy . . . (250J - 75J) = 175J useful energy.

(useful energy) / (energy supplied) = (175J) / (250J) = 70% efficiency

================================

Way #2:

How much of the energy is wasted ? . . . 75J wasted

What percentage of the Input is that 75J ? . . . 75/250 = 30% wasted

30% of the input energy is wasted. That leaves the other 70% to be useful energy.

jek_recluse [69]2 years ago

3 0

Answer:

70%

Explanation:

I did the USA Test Prep.

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alexandr1967 [171]

The correct answer is C. Plug in x and y value for answers to see if they work. For example, 9/3 = 3. So C is the answer.

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3 years ago

If force remains constant and acceleration decreases what must happen to the mass

blondinia [14]

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3 years ago

Which term is defined as an elongated area of low pressure?

fenix001 [56]

Answer:

A trough

Explanation:

A trough is an elongated area of relatively low pressure extending from the center of a region of low pressure.

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3 years ago

A wire loop is suspended from a string that is attached to point P in the drawing. When released, the loop swings downward, from

Naddik [55]

Complete Question

The complete question iws shown on the first uploaded image

Answer:

$y \to z \to x$

$x \to z \to y$

Explanation:

Now looking at the diagram let take that the magnetic field is moving in the x-axis

Now the magnetic force is mathematically represented as

$F = I L$ x B

Note (The x is showing cross product )

Note the force(y-axis) is perpendicular to the field direction (x-axis)

Now when the loop is swinging forward

The motion of the loop is from y to z to to x to y

Now since the force is perpendicular to the motion(velocity) of the loop

Hence the force would be from z to y and back to z

and from lenze law the induce current opposes the force so the direction will be from y to z to x

Now when the loop is swinging backward

The motion of the induced current will now be x to z to y

5 0

3 years ago

The speed that a tsunami can travel is modeled by the equation , where s is the speed in kilometers per hour and d is the averag

CaHeK987 [17]

The speed of tsunami is a.0.32 km.

Steps involved :

The equation s = 356d models the maximum speed that a tsunami can move at. It reads as follows: s = 200 km/h d =?

Let's now change s to s in the equation to determine d: s = 356√d 200 = 356√d √d = 200 ÷ 356 √d = 0.562 Let's square the equation now by squaring both sides: (√d)² = (0.562) ² d = (0.562)² = 0.316 ≈ 0.32

As a result, 0.32 km is roughly the depth (d) of water for a tsunami moving at 200 km/h.

To learn more about tsunami refer : brainly.com/question/11687903

#SPJ4

6 0

1 year ago