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2 years ago

7

An electric motor uses 670 kJ of electrical energy to generate 595 kJ of mechanical kinetic energy. What is the efficiency of th

e motor?
Full example, please...
Thank you!

1 answer:

stellarik [79]2 years ago

4 0

Used energy=595KJ
Total energy=670KJ

Efficiency:-

$\\ \tt\longmapsto \dfrac{595}{\cancel{670}}\times \cancel{100}$

$\\ \tt\longmapsto \dfrac{595}{67}\times 10$

$\\ \tt\longmapsto 8.88(10)$

$\\ \tt\longmapsto 88.8\%$

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A bowling ball has a mass of 6 kg. What happens to its momentum when its speed increases from 2 m/s to 4 m/s?

mash [69]

Answer:

B) The initial momentum is 12 kg*m/s, and the final momentum is 24 kg*m/s

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The momentum of an object is given by the product between its mass (m) and its velocity (v):

$p=mv$

Let's apply this formula to calculate the initial momentum and final momentum of the ball:

- initial momentum:

$p_i = m v_i = (6 kg)(2 m/s)=12 kg m/s$

- Final momentum:

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So, the correct answer is

B) The initial momentum is 12 kg*m/s, and the final momentum is 24 kg*m/s

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2 years ago

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Answer:

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Explanation:

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As we know, Electric field = E = kQ/r.r

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3 years ago

A ball is thrown straight up at 20 m. What is the balls velocity as it hits the ground?

deff fn [24]

Answer:

<em>The velocity of the ball as it hit the ground = 19.799 m/s</em>

Explanation:

Velocity: Velocity of a body can be defined as the rate of change of displacement of the body. The S.I unit of velocity is m/s. velocity is expressed in one of newtons equation of motion, and is given below.

v² = u² + 2gs.......................... Equation 1

Where v = the final velocity of the ball, g = acceleration due to gravity, s = the height of the ball

<em>Given: s = 20 m, u = 0 m/s</em>

<em>Constant: g = 9.8 m/s²</em>

<em>Substituting these values into equation 1,</em>

<em>v² = 0 + 2×9.8×20</em>

<em>v² = 392</em>

<em>v = √392</em>

<em>v = 19.799 m/s.</em>

<em>Therefore the velocity of the ball as it hit the ground = 19.799 m/s</em>

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3 years ago

A cube of wood having an edge dimension of 20.0cm and a density of 650 kg /m³ floats on water. (b) What mass of lead should be p

schepotkina [342]

The mass added is "m" so the complete cube is submerged in the water is 2.8 kg.

<h3>What mass of lead should be placed on the cube?</h3>

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Substituting the values in the above equation, we get

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ρ is the density of the water

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h = a − x

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h = 0.2 − 0.13

h = 0.07 m

b) The mass added is "m" so the complete cube is submerged in the water, therefore

ρcgV + mg = ρg × (V)

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The mass added is "m" so the complete cube is submerged in the water is 2.8 kg.

To learn more about buoyant force refer to:

brainly.com/question/11884584

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1 year ago

What is the slope of the line plotted below?

lubasha [3.4K]

Answer:

Slope is in fact -2

Explanation:

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