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nirvana33 [79]
3 years ago
15

Work and power!!

Physics
1 answer:
Gnesinka [82]3 years ago
6 0

Answer:

Efficiency

Explanation:

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The concept that large masses warp the shape of spacetime and thus change the path of an object moving through that spacetime ap
mrs_skeptik [129]

Answer: Newton's law of gravity theory disagrees with Einstein's theory. The last one were named Theory of General Relativity and was discovered and proposed by the physicist Einstein in the year of 1915.

Explanation: Until the beginning of 20 century, the physics were ruled by Isaac Newton's ideas. He believed that the gravity was a force caused by the objects mass on the space, made them to be draw towards each other. Newton thought that the greater the mass of the object, the more intense was its attraction, which would justify the planet's moovements around the sun and how the gravity between them maintain the planets on solar orbit. Concluding, he believed gravity was a immediate force of action, regardless of the distance of the bodies.

Contrary to Newton's law of gravity, in 1915, the physicist Einstein created the Theory of General Relativity, wich discovered that gravity was, in fact, the deformation caused by the attraction of massive celestial bodies. This deformation, related to the Sun, for example, creates a curvature on the space-time and this curvature are followed by the other planets.

So, we can conclude that Newton's law of gravity disagree's with the Theory of General Relativity, once the first believes that light force of attraction are transmitted instantly and, as Einstein already prooved, the gravity influency propagates in the speed of light.

4 0
3 years ago
Birds resting on high-voltage power lines are a common sight. the copper wire on which a bird stands is 1.28 cm in diameter and
nekit [7.7K]

Answer:

8\cdot 10^{-4} V

Explanation:

First of all, let's find the cross-sectional area of the copper wire. The radius of the wire half the diameter:

r=\frac{d}{2}=\frac{1.28 cm}{2}=0.64 cm=6.4\cdot 10^{-3} m

So the area is

A=\pi r^2 = \pi (6.4\cdot 10^{-3} m)^2=1.29\cdot 10^{-4} m^2

Now we can calculate the resistance of the piece of copper wire between the bird's feet, with the formula:

R=\rho \frac{L}{A}

where

\rho=1.68\cdot 10^{-8} \Omega m is the resistivity of copper

L=4.12 cm=4.12 \cdot 10^{-2} m is the length of the piece of wire

A=1.29\cdot 10^{-4} m^2 is the cross-sectional area

Substituting, we find

R=(1.68\cdot 10^{-8} m^2)\frac{4.12\cdot 10^{-2} m}{1.29\cdot 10^{-4} m^2}=5.4\cdot 10^{-6} \Omega

And since we know the current in the wire, I=149 A, we can now find the potential difference across the body of the bird, by using Ohm's law:

V=IR=(149 A)(5.4\cdot 10^{-6} \Omega)=8\cdot 10^{-4} V

4 0
3 years ago
Explain why an X-linked recessive trait is expressed more commonly in males than in females.
masya89 [10]

Answer:

X-linked recessive inheritance

A male with a mutation in a gene on the X chromosome is typically affected with the condition. Because females have two copies of the X chromosome and males have only one X chromosome, X-linked recessive diseases are more common among males than females.

5 0
3 years ago
Read 2 more answers
A car starts from rest and accelerates uniformly over a time of 7.25 seconds for a distance of 210 m. Determine the acceleration
lara31 [8.8K]

Answer:

Acceleration is 7.990487515m/s²

Initial velocity is 0m.s

Explanation:

s=ut+(1/2)at²

210=0(7.25)+(1/2)a(7.25²)

210=26.28125a

∴a=7.990487515m/s²

'Vi' or 'u' is the inital speed. Since it starts from rest, this equals 0.

8 0
3 years ago
A 70.0-kilogram man is walking at a speed if 2.0 m/s. What is the kinetic energy?
Paraphin [41]

Answer:

140 J

Explanation:

From the the question, the mass of the man =70.0 kg and the speed at which the man is walking =2.0 m/s.

K.E =  \frac{1}{2}m {v}^{2}

where K.E = the kinetic energy, m=mass and v= speed.

By substitution,

K.E =  \frac{1}{2} \times 70 \times  {2}^{2}

\implies \: K.E = \frac{280}{2}

\implies K.E =140

Hence the kinetic energy of the man is 140J

3 0
3 years ago
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