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4 years ago

A runner achieves a velocity of 12.1 m/s 8.2 sec after he begins. What is

Physics

1 answer:

Karo-lina-s [1.5K]4 years ago

7 0

Given - 

Velocity (v) = 12.1 m/s
Time (t) = 8.2 sec

To find -

Acceleration

Solution - 

★ Acceleration = velocity/ time

→ A = 12.1/8.2

→ 1.47.... m/s²

Therefore, the acceleration of the runner will be 1.47 m/s².

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An electromagnetic wave is traveling through free space. The amplitudes of the wave's electric and magnetic fields are E 0 E0 an

Sauron [17]

Answer:

B = Bo / 2

Explanation:

Magnesium and electric fields are related in an electromagnetic wave

E / B = c

If the electric field is halved the magnetic field must also be halved to meet the written equation

B = Bo / 2

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3 years ago

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Which organelle acts like the transportation or circulatory system of the cell?

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The endoplasmic rectiulum... hope this helps!

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3 years ago

¿Cuál es la intensidad del campo eléctrico a una distancia de 2 m de una carga de -12μC? *

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Answer:

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3 years ago

A thin spherical spherical shell of radius R which carried a uniform surface charge density σ. Write an expression for the volum

ozzi

Answer:

Explanation:

From the given information:

We know that the thin spherical shell is on a uniform surface which implies that both the inside and outside the charge of the sphere are equal, Then

The volume charge distribution relates to the radial direction at r = R

∴

$\rho (r) \ \alpha \ \delta (r -R)$

$\rho (r) = k \ \delta (r -R) \ \ at \ \ (r = R)$

$\rho (r) = 0\ \ since \ r< R \ \ or \ \ r>R---- (1)$

To find the constant k, we examine the total charge Q which is:

$Q = \int \rho (r) \ dV = \int \sigma \times dA$

$Q = \int \rho (r) \ dV = \sigma \times4 \pi R^2$

∴

$\int ^{2 \pi}_{0} \int ^{\pi}_{0} \int ^{R}_{0} \rho (r) r^2sin \theta \ dr \ d\theta \ d\phi = \sigma \times 4 \pi R^2$

$\int^{2 \pi}_{0} d \phi* \int ^{\pi}_{0} \ sin \theta d \theta * \int ^{R}_{0} k \delta (r -R) * r^2dr = \sigma \times 4 \pi R^2$

$(2 \pi)(2) * \int ^{R}_{0} k \delta (r -R) * r^2dr = \sigma \times 4 \pi R^2$

Thus;

$k * 4 \pi \int ^{R}_{0} \delta (r -R) * r^2dr = \sigma \times R^2$

$k * \int ^{R}_{0} \delta (r -R) r^2dr = \sigma \times R^2$

$k * R^2= \sigma \times R^2$

$k = R^2 --- (2)$

Hence, from equation (1), if k = $\sigma$

$\mathbf{\rho (r) = \delta* \delta (r -R) \ \ at \ \ (r=R)}$

$\mathbf{\rho (r) =0 \ \ at \ \ rR}$

To verify the units:

$\mathbf{\rho (r) =\sigma \ * \ \delta (r-R)}$

↓ ↓ ↓

c/m³ c/m³ × 1/m

Thus, the units are verified.

The integrated charge Q

$Q = \int \rho (r) \ dV \\ \\ Q = \int ^{2 \ \pi}_{0} \int ^{\pi}_{0} \int ^R_0 \rho (r) \ \ r^2 \ \ sin \theta \ dr \ d\theta \ d \phi \\ \\ Q = \int ^{2 \pi}_{0} \ d \phi \int ^{\pi}_{0} \ sin \theta \int ^R_{0} \rho (r) r^2 \ dr$

$Q = (2 \pi) (2) \int ^R_0 \sigma * \delta (r-R) r^2 \ dr$

$Q = 4 \pi \sigma \int ^R_0 * \delta (r-R) r^2 \ dr$

$Q = 4 \pi \sigma *R^2$ since $( \int ^{xo}_{0} (x -x_o) f(x) \ dx = f(x_o) )$

$\mathbf{Q = 4 \pi R^2 \sigma }$

6 0

3 years ago

Which of ONE of the following four elements has the most metallic properties?

olchik [2.2K]

Answer:

12 (Magnesium- Mg)

Explanation:

Looking at the four numbers, we have:

Magnesium, Silicon, Sulfur, and Chlorine.

We can eliminate two of the answers immediately just by looking at the periodic table.

Sulfur and Chlorine are on the nonmetal side of the periodic table. So that's definitely not it. That leaves Magnesium and Silicon.

Silicon is a Metalloid. Magnesium is an Alkaline earth Metal.

Metaloids are elements that have a mix of both metal and nonmetal properties (luster, how it feels, etc.). Since it's a MIX and Magnesium is just straight METAL-

We can say Magnesium has the most metallic properties.

hope this helps!!

7 0

3 years ago