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Tems11 [23]
3 years ago
14

A student runs up a flight of stairs which info is not needed to calculate the rate of the student is doing work against gravity

A the height of the flight of stairs B the length of flight of stairs C the time taken to run up the stairs D the weight of the student
Physics
1 answer:
NikAS [45]3 years ago
8 0

Answer:

B.

Explanation:

Given that a student runs up a flight of stairs which info is not needed to calculate the rate of the student is doing work against gravity A the height of the flight of stairs B the length of flight of stairs C the time taken to run up the stairs D the weight of the student

The rate of doing work is known as power.

Power = work done/time

Work done = energy = mgh

Since energy = mgh

Where mg = weight

And h = height

Time = time taken to run up the stairs.

Time, weight mg and height h will be needed while the Length of the flight is therefore not needed.

The correct answer is B.

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If you were trying to describe the difference between power and work you could say...?
Paha777 [63]

Answer:

Look to the explanation

Explanation:

<u><em>Work done</em></u> is  is the energy transferred to or from an object by means

of a force acting on the object.

Work is positive if energy transferred to the object, and  work is

negative if energy transferred from the object.

<em>Work = Force in the direction motion of object × its displacement</em>

W=F*s

The SI unit of the work is joule (J)

<u><em>Power</em></u> is the rate of work

<em>Power = work done ÷ time taken</em>

Power = \frac{F*s}{t}

Displacement (s) ÷ time (t) = velocity (v)

<em>Power = Force × velocity</em>

P=F*v

The SI unit of the power is watt (w)

6 0
3 years ago
Two resistors are to be combined in parallelto form an equivalent resistance of 400Ω. The resistors are takenfrom available stoc
vivado [14]

Answer:

ΔR_{e} = 84   Ω,     R_{e} = (40 ± 8) 10¹   Ω

Explanation:

The formula for parallel equivalent resistance is

          1 / R_{e} = ∑ 1 / Ri

In our case we use a resistance of each

           R₁ = 500 ± 50  Ω

          R₂ = 2000 ± 5%

This percentage equals

        0.05 = ΔR₂ / R₂

        ΔR₂ = 0.05 R₂

        ΔR₂ = 0.05 2000 = 100   Ω

We write the resistance

        R₂ = 2000 ± 100    Ω

We apply the initial formula

        1 / R_{e} = 1 / R₁ + 1 / R₂

        1 / R_{e} = 1/500 + 1/2000 = 0.0025

        R_{e}  = 400    Ω

Let's look for the error  (uncertainly) of Re

      R_{e} = R₁R₂ / (R₁ + R₂)

       R’= R₁ + R₂

       R_{e} = R₁R₂ / R’

Let's look for the uncertainty of this equation

      ΔR_{e} / R_{e} = ΔR₁ / R₁ + ΔR₂ / R₂ + ΔR’/ R’

The uncertainty of a sum is

      ΔR’= ΔR₁ + ΔR₂

We substitute the values

     ΔR_{e} / 400 = 50/500 + 100/2000 + (50 +100) / (500 + 2000)

     ΔR_{e} / 400 = 0.1 + 0.05 + 0.06

     ΔR_{e} = 0.21 400

     ΔR_{e} = 84   Ω

Let's write the resistance value with the correct significant figures

    R_{e} = (40 ± 8) 10¹   Ω

6 0
3 years ago
What generalization can be made about energy?
HACTEHA [7]
Well, energy can be produced from the burning of fossil fuels which produce steam to spin turbines which generates electricity. But fossil fuels like coal and oil are no renewable.
Some renewable ways to get energy is water where they separate hydrogen from h2o because hydrogen can be made into energy. Also nuclear fission is another way to get energy. That's when in a nuclear power plant, the atoms nucleus is split which sends a large amount of energy.
Wind energy is another source of energy, which is from windmills. Another renewable energy source is solar energy. That's when u use solar cells, like some houses and calculators have, which generates a lot of energy, but only in the day since the sun doesn't shine in the nigh.


Hope I helped!!!

6 0
3 years ago
Read 2 more answers
A 55.6 kg ice skater is moving at 1.73 m/s when she grabs the loose end of a rope, the opposite end of which is tied to a pole.
GarryVolchara [31]

Answer:

The force exerted by the rope on her arms is 273.7 N = 0.274 kN

Explanation:

Step 1: Data given

Mass of the ice skater = 55.6 kg

Velocity = 1.73 m/s

She then moves in a circle of radius 0.608 m around the pole.

Step 2:

Force exterted by the horizontal rope is the centripetal force acting on theice skater:

Fc = M*ac

⇒ with ac = v²/r

Fc = M * v²/r

Fc = 55.6 * 1.73²/0.608

Fc =273.69 N

The force exerted by the rope on her arms is 273.7 N = 0.274 kN

7 0
3 years ago
What are beats
N76 [4]

Beats can be defined as the periodic fluctuations in the frequency of sound waves. That is option D

<h3>What are sound waves?</h3>

Sound waves are those waves that are produced by the vibration of an object whose energy is usually propagated through a medium.

When two sound waves of different frequencies meets, a periodic variation that occurs is called beats.

Therefore, Beats can be defined as the periodic fluctuations in the frequency of sound waves.

Learn more about waves here:

brainly.com/question/15663649

#SPJ1

4 0
2 years ago
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