Help please!!

The wires leading to and from a 0.12-mm-diameter lightbulb filament are 1.5 mm in diameter. The wire to the filament carries a c

OleMash [197]

Answer:

The current in the filament is 0.81 A

Explanation:

Given :

Diameter of wire $d_{1} = 0.12 \times 10^{-3}$ m

Diameter of filament $d_{2} = 1.5 \times 10^{-3}$ m

Current density $J = 4.6 \times 10^{5} \frac{A}{m^{2} }$

From the formula of current density,

$J = \frac{I}{A}$

Where $A =$ area = $\frac{\pi d^{2} }{4}$

Current in the filament is given by,

$I = JA$

Area of filament is given by $A = \pi \frac{(1.5 \times 10^{-3} )^{2} }{4}$

$A = 1.76 \times 10^{-6}$

Put value of A in above equation,

$I = 4.6 \times 10^{5} \times 1.76 \times 10^{-6}$

$I = 0.81$ A

Therefore, current in the filament is 0.81 A

4 0

3 years ago

Which sets of data show a wave with the shortest wavelength? A. Speed=100 million m/s and frequency = 50 million Hz. B. Speed=15

SashulF [63]

The answer is A. Speed=100 million m/s and frequency = 50 million Hz.

Let's calculate for each choice the wavelength using the equation:
v = f × λ ⇒ λ = v ÷ f

where:
v - the speed,
f - the frequency,
λ - the wavelength.

A:
v = 100 000 000 m/s
f = 50 000 000 Hz = 50 000 000 1/s (Since f = 1/T, so units are Hz = 1/s)
⇒ λ = 100 000 000 ÷ 50 000 000 = 2 m

B:
v = 150 000 000 m/s
f = 1 500 Hz = 1 500 1/s
⇒ λ = 150 000 000 m/s ÷ 1 500 = 100 000 m

B:
v = 300 000 000 m/s
f = 100 Hz = 100 1/s
⇒ λ = 300 000 000 m/s ÷ 100 = 3 000 000 m

According to these calculations, the shortest wavelength is needed for choice A.

3 0

3 years ago

Mathematically, explain how a car (A) with mass of 500 kg and velocity of 2 m/s has the same kinetic energy as a car (B) with ma

scoray [572]

Answer:

Both kinetic energies are equal

Explanation:

Kinetic Energy

Is the type of energy of an object due to its state of motion. It's proportional to the mass and the square of the speed.

The equation for the kinetic energy is:

$\displaystyle K=\frac{1}{2}mv^2$

Where:

m = mass of the object

v = speed of the object

The kinetic energy is expressed in Joules (J)

There are two cars:

Car (A) with mass ma=500 kg and speed va= 2 m/s

Car (B) with mass mb=20,000 gr and speed vb= 10 m/s

Calculate the kinetic energy of both cars:

$\displaystyle K_a=\frac{1}{2}m_av_a^2$

$\displaystyle K_a=\frac{1}{2}500*2^2$

$\displaystyle K_a=250*4=1,000 J$

To calculate the Kb, the mass must be expressed in kg:

mb=20,000/1,000 =20 Kg

$\displaystyle K_b=\frac{1}{2}m_bv_b^2$

$\displaystyle K_b=\frac{1}{2}20*10^2$

$\displaystyle K_b=10*100=1,000 J$

Both kinetic energies are equal

8 0

3 years ago

what is the relationship between high frequency and short wavelength? Low frequency and long wavelength?

larisa [96]

Answer:

The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength.

5 0

3 years ago

Describe how asteroids meteors and cometsmove around the solar system

Arturiano [62]

Answer:

Explanation:

While traveling through space, asteroids sometimes collide with each other and break up into smaller fragments. Comets shed dust as they roam the solar system. These 'break ups' result in numerous small particles and fragments, called meteoroids, which orbit the sun. ... Thus a meteor, or shooting star, is formed.

7 0

3 years ago

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