Explain why people have different skin colors?

A rugby player runs with the ball directly toward his opponent's goal, along the positive direction of an x axis. He can legally

Over [174]

Answer:

minimum angle is 128.69°

Explanation:

given data

player velocity with respect ground v1 = 3.5 m/s

ball velocity with respect himself v2 = 5.6 m/s

to find out

smallest angle

solution

we know ball velocity with respect field will be

ball velocity = v1 +v2

ball velocity = 3.5 + 5.6 = 9.1m/s

we consider angle that player hit ball is θ

then by as per figure triangle

cosθ = $\frac{v1}{v2}$

cosθ = $\frac{3.5}{5.6}$

θ = 51.31

so minimum angle is 180 - 51.31 = 128.69°

6 0

3 years ago

Two parallel plates that are initially uncharged are separated by 1.7 mm, have only air between them, and each have surface area

yaroslaw [1]

Answer:

$5.63\cdot 10^{-6} C$

Explanation:

The capacitor of a parallel-plate capacitor is given by:

$C=\epsilon_0 \frac{A}{d}$

where

A is the area of each plate

d is the separation between the plates

$\epsilon_0$ is the vacuum permittivity

The energy stored in a capacitor instead is given by

$U=\frac{1}{2}\frac{Q^2}{C}$

where

Q is the charge stored in each plate

Substituting the expression we found for C inside the last formula,

$U=\frac{1}{2}\frac{Q^2 d}{\epsilon_0 A}$

And re-arranging it

$Q=\sqrt{\frac{2U\epsilon_0 A}{d}}$

Now if we substitute

$d=1.7 mm=0.0017 m\\A=16 cm^2 = 16\cdot 10^{-4} m^2\\U = 1.9 J$

We find the charge stored on the capacitor:

$Q=\sqrt{\frac{2(1.9)(8.85\cdot 10^{-12})(16\cdot 10^{-4})}{0.0017}}=5.63\cdot 10^{-6} C$

7 0

3 years ago

Which of the following statements are true concerning electromagnetic radiation fields?Select all that apply.a.) The electric an

ale4655 [162]

Answer:

a.) The electric and magnetic fields are in phase with each other as they propagate through space.

Explanation:

Electromagnetic wave is a transverse wave in which magnetic field and electric field both induces each other as both changes with time

Here magnetic field induces electric field and similarly magnetic field induces electric field.

As we know that this is a transverse wave so here magnetic field and electric field lies in perpendicular planes. but they both propagate in same direction in such a wave that both fields reaches their maximum position and minimum positions simultaneously

So the correct answer is

a.) The electric and magnetic fields are in phase with each other as they propagate through space.

6 0

3 years ago

Bicycle in its writers have combined a mass of 80 kg in a speed of 6.0 meters per Second what is the magnitude of the average fo

erik [133]

Answer:

F = 120 N

Explanation:

Force x distance = energy

The bike has energy 1/2 . 80 . 6^2 = 1440 J

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