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slava [35]
3 years ago
12

A certain wire has a length l and a resistance r. It is stretched uniformly to a length of 2l. The resistance of the wire after

it has been stretched is
Physics
1 answer:
skelet666 [1.2K]3 years ago
8 0

I am not sure whether this is the right way to go about answering the question.

The resistance of a wire is proportional to its length, therefore doubling the length should double the resistance. But resistance is also proportional to the inverse square of the wire's cross-sectional area, and stretching the wire seems to imply increasing its length and decreasing its cross-sectional area, which would increase the resistance more than simply increasing its length.

I'll just say to only care about the effect of increasing the wire's length. Due to the wire's length now being 2l, the new resistance is 2r.

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Between 1911 and 1990, the top of the leaning bell tower at Pisa, Italy, moved toward the south at an average rate of 1.2 mm/y.T
Anit [1.1K]

Answer:

Angular speed, \omega=6.90\times 10^{-13}\ rad/s

Explanation:

It is given that,    

The top of the leaning bell tower at Pisa, Italy, moved toward the south at an average rate of, v = 1.2 mm/yr

1\ mm/yr=3.171\times 10^{-11}\ m/s

Velocity, v=3.80\times 10^{-11}\ m/s

Height of the tower, h = 55 m

The height of the tower is equivalent to the radius. Let \omega is the angular speed of the tower’s top about its base. The relation between the angular speed and the angular speed is given by :

v=r\omega

\omega=\dfrac{v}{r}

\omega=\dfrac{3.80\times 10^{-11}\ m/s}{55\ m}

\omega=6.90\times 10^{-13}\ rad/s

So, the average angular speed of the tower’s top about its base is 6.90\times 10^{-13}\ rad/s. Hence, this is the required solution.

6 0
3 years ago
Water flows over a section of Niagara Falls at the rate of 1.2×106 kg/s and falls 50.0 m. How much power is generated by the fal
quester [9]

Answer:

5.88×10⁸ W

Explanation:

Power = energy / time

P = mgh / t

P = (m/t) gh

P = (1.2×10⁶ kg/s) (9.8 m/s²) (50.0 m)

P = 5.88×10⁸ W

7 0
3 years ago
How does a nuclear power plant produce energy
nalin [4]
The steam then turns turbines to produce<span> electricity. The difference is that </span>nuclear plants do<span> not burn anything. Instead, they use uranium fuel, consisting of solid ceramic pellets, to </span>produce<span> electricity through a process called fission. best i can do hope it helps</span>
8 0
3 years ago
A 5.00-g bullet is fired into a 900-g block of wood suspended as a ballistic pendulum. The combined mass swings up to a height o
Thepotemich [5.8K]

Answer:

The value is  KE_b =0.710 \ J

Explanation:

From the question we are told that

   The mass  of the bullet is m_b  = 5.00 \ g  = 0.005 \  kg

  The mass  of the wood is  m_w =  900 \  g  =  0.90\  kg

   The height attained by the combined mass is  h =  8.0 \ cm  =  0.08 \ m

Generally according to the law of energy conservation    

    KE _b  =  PE_c

Here KE_b is the kinetic energy of the bullet before collision.

and PE_c is the  potential  energy of the combined mass of bullet and wood at the height h which is mathematically represented as

      PE_m  =  [m_b  + m_w] *  g *  h

So

   KE_b =PE_c   = [0.005  + 0.90] * 9.8 *0.08

=> KE_b =0.710 \ J

3 0
3 years ago
Astronaut Rob leaves Earth in a spaceship at a speed of 0.960c relative to an observer on Earth. Rob's destination is a star sys
olchik [2.2K]

Answer:

A) 15.0 years

Explanation:

Due to the distance to the star system is in light-year units, we can compute the time by using:

t=\frac{d}{v}=\frac{14.4 l-y}{0.960}=15l-y

then, Rob will take to complete the trip about 15 light-years.

hope this helps!!

7 0
3 years ago
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