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2 years ago

Which of the following would reduce the resistance of a metal wire?

Physics

2 answers:

Vlad [161]2 years ago

8 0

1 ) a) increasing its thickness

2) c)potential difference

harina [27]2 years ago

6 0

A. and c. are the correct choices respectively.

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Ideal mechanical advantage is equal to the displacement of the effort force divided by the displacement of the load.

ELEN [110]

This would be false. hope this helps. good luck :)

3 0

2 years ago

Some miners wish to remove water from a mine shaft. A pipe is lowered to the water 90 m below, and a negative pressure is applie

WITCHER [35]

Answer:

Explanation:

Given

Pipe is lowered to the water $h=90\ m$

Negative Pressure is applied to raise the water

Pressure is given by

$P=\rho gh$

where $P=pressure$

$\rho =Density$

$h=depth$

$P=10^3\times 9.8\times 90$

$P=8.82\times 10^{5}\ N/m^2\approx 8.82\ atm$

(b)8.82 atm is much lower than the vapor pressure of water

(c)The fact of applying a negative pressure of 8.74 below the vapor pressure of water

4 0

3 years ago

A small plastic bead has been charged to -15nC.

marishachu [46]

Answer:

Explanation:

q = - 15 n C = - 15 x 10^-9 c

(a) d = 0.9 cm = 0.009 m

electric field on proton, E = Kq/d²

E = 9 x 10^9 x 15 x 10^-9 / (0.009)²

E = 1.67 x 10^6 N/C

Force on proton, F = charge on proton x Electric field

F = 1.6 x 10^-19 x 1.67 x 10^6 = 2.67 x 10^-13 N

acceleration of proton, a = F / m

a = (2.67 x 10^-13) / (1.67 x 10^-27)

a = 1.6 x 10^14 m/s²

(B) the direction of acceleration is towards the bead, as the force is attractive.

electric field on proton, E = Kq/d²

E = 9 x 10^9 x 15 x 10^-9 / (0.009)²

E = 1.67 x 10^6 N/C

Force on electron, F = charge on electron x Electric field

F = 1.6 x 10^-19 x 1.67 x 10^6 = 2.67 x 10^-13 N

acceleration of proton, a = F / m

a = (2.67 x 10^-13) / (9.1 x 10^-31)

a = 3 x 10^17 m/s²

(D) the direction of acceleration is away from the bead, as the force is repulsive.

8 0

2 years ago

A charging RC circuit controls the intermittent windshield wipers in a car. The emf is 12.0 V. The wipers are triggered when the

lilavasa [31]

Answer:

$R=803k\Omega$

Explanation:

We have the following information,

$V_0 = 12V\\V=10V\\c= 1.25*10^{-6}F\\t=1.8s$

We apply the equation for capacitor charging the voltage across it,

$V=V_0 (1-e^{-t/x})\\e^{-t/x}=1-(\frac{V}{V_0})\\-\frac{t}{Rc}=ln(\frac{V}{V_0})\\R=-\frac{t}{ln(\frac{V}{V_0})*c}$

Replacing values,

$R=-\frac{1.8}{ln(10/12)*1.25*10^{-6}}$

$R=803k\Omega$

3 0

2 years ago

A laser used to dazzle the audience at a rock concert emits blue light with a wavelength of 463 nm . calculate the frequency of

ZanzabumX [31]

The wavelength of light is given as 463 nm or can also be written as 463 x 10^-9 m. [wavelength = ʎ]

We know that the speed of light is 299 792 458 m / s or approximately 3 x 10^8 m / s. [speed of light = c]

Given the two values, we can calculate for the frequence (f) using the formula:

f = c / ʎ

Substituting the given values:

f = (3 x 10^8 m / s) / 463 x 10^-9 m

f = 6.48 x 10^14 / s = 6.48 x 10^14 s^-1

5 0

2 years ago