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3 years ago

A wire of length L and cross-sectional area A has resistance R.

Physics

2 answers:

lara31 [8.8K]3 years ago

4 0

Answer:

The resistance will be twice the original resistance

Explanation:

This is a fairly simple question, the formular for the resistance of a wire is given as

R = rho *length / area

Where R = resistance

Rho = resistivity

L = length

A = area

Since the density and area are constant I.e they do not change

R/ length = rho/ area

The initial length is given as L, when this length is stretched to twice its original length ,it becomes 2×L = 2L

Let x represent the resistance when the length is doubled

R/ L = x / 2L

x = 2LR / L ; dividing by L

We have that x = 2R ; twice the resistance

soldi70 [24.7K]3 years ago

4 0

Answer:

Explanation:

Given:

L2 = 2 × L1

Using the formula,

Resistivity, d = (R × A)/L

Where,

R = resistance

A = area

L = length

1. d1 = (R1 × A1)/L1

2. d2 = (R2 × A2)/L2

Equating both 1 and 2 together,

(R2 × A2)/L2 = (R1 × A1)/L1

(R2 × A2)/(2 × L1) = (R1 × A1)/L1

Assume A1 = A2,

R2 = [(R1 × A1) × 2 × L1]/(A1 × L1)

R2 = 2 × R1

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r is the distance measured from the centre of the planet.

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And now we can use the previous equation to calculate the field strength at that altitude:
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And we can see this value is a bit less than the gravitational strength at the surface, which is $g_s = 9.81 m/s^2$ .

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3 years ago

A wheel rotates with a constant angular acceleration of  rad/s2. During a certain time interval its angular displacement is  r

Hatshy [7]

Answer:

The angular velocity at the beginning of the interval is $\pi\sqrt{2}\ rad/s$ .

Explanation:

Given that,

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Angular velocity $\omega =2\pi\ rad/s$

We need to calculate the angular velocity at the beginning

Using formula of angular velocity

$\alpha =\dfrac{\omega^2-\omega_{0}^2}{2\theta}$

$\omega_{0}^2=\omega^2-2\alpha\theta$

Where, $\alpha$ = angular acceleration

$\omega$ = angular velocity

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$\omega_{0}^2=(2\pi)^2-2\times\pi\times\pi$

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3 years ago

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Elis [28]

Answer:

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Explanation:

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3 years ago

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padilas [110]

Momentum, p = m.v
m of the girl = 60.0 kg
m of the boat = 180 kg
v of the girl = 4.0 m/s

A) Momentum of the girl as she is diving:
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B) momentum of the raft = - momentum of the girl = -24.0 N/s

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3 years ago

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irga5000 [103]

Answer: Option (c) is the correct answer.

Explanation:

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Hence, liquid state of a substance will change into vapor state of the substance. This means that an increase in temperature will lead to an increase in vapor pressure of the substance.

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3 years ago