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3 years ago

A runner traveled 15 kilometers north then backtracked 11 kilometers south before stopping. His resultant displacement was

Physics

2 answers:

Vanyuwa [196]3 years ago

5 0

displacement is 4 km in north direction.

Explanation:

we are given

A runner traveled 15 kilometers north first

then backtracked 11 kilometers south

we have to find displacement=d=?

assume that east side represents +ve x- axis(horizontal)

and

north represent +ve y - axis (vertical)

we can take x-axis (horizontal) as i

and y-axis (vertical) as j.

Displacement = 15 j -11 j = 4 km north

Serhud [2]3 years ago

4 0

<u>Answer:</u>

Resultant displacement is 4 km north.

<u>Explanation:</u>

Let east represents positive x- axis and north represent positive y - axis. Horizontal component is i and vertical component is j.

A runner traveled 15 kilometers north then backtracked 11 kilometers south before stopping,

So initial displacement, 15 kilometers north = 15 j km

Second displacement, 11 kilometers south = -11 j km

Total displacement = 15 j -11 j = 4 j km

Total displacement is 4 km north.

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erastova [34]

Answer:

* most of the emission would be in the infrared part, the visible radiation would be very small.

*total intensity of the semition decreases that the intensity depends on the fourth power of the temperature

Explanation:

The radiation emitted by the Sun is approximately the radiation of a black body, if the Sun were to cool, the maximum emission wavelength changes

λ T = 2,898 10⁻³

λ = 2,898 10⁻³ / T

if the temperature decreases the maximum wavelength the greater values are moved, that is to say towards the infrared. Therefore the emission curve also moves, in this case most of the emission would be in the infrared part, the visible radiation would be very small.

Furthermore, the total intensity of the semition decreases that the intensity depends on the fourth power of the temperature according to Stefan's law

P = σ A eT⁴

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3 years ago

Write equations for both the electric and magnetic fields for an electromagnetic wave in the red part of the visible spectrum th

Strike441 [17]

Answer:

$E=3.5(8.98*10^{6}x-2.69*10^{15}t)$

$B=1.17*10^{-8}(8.98*10^{6}x-2.69*10^{15}t)$

Explanation:

The electric field equation of a electromagnetic wave is given by:

$E=E_{max}(kx-\omega t)$ (1)

E(max) is the maximun value of E, it means the amplitude of the wave.
k is the wave number
ω is the angular frequency

We know that the wave length is λ = 700 nm and the peak electric field magnitude of 3.5 V/m, this value is correspond a E(max).

By definition:

$k=\frac{2\pi}{\lambda}$

$k=8.98*10^{6} [rad/m]$

And the relation between λ and f is:

$c=\lambda f$

$f=\frac{c}{\lambda}$

$f=\frac{3*10^{8}}{700*10^{-9}}$

$f=4.28*10^{14}$

The angular frequency equation is:

$\omega=2\pi f$

$\omega=2\pi*4.28*10^{14}$

$\omega=2.69*10^{15} [rad/s]$

Therefore, the E equation, suing (1), will be:

$E=3.5(8.98*10^{6}x-2.69*10^{15}t)$ (2)

For the magnetic field we have the next equation:

$B=B_{max}(kx-\omega t)$ (3)

It is the same as E. Here we just need to find B(max).

We can use this equation:

$E_{max}=cB_{max}$

$B_{max}=\frac{E_{max}}{c}=\frac{3.5}{3*10^{8}}$

$B_{max}=1.17*10^{-8}T$

Putting this in (3), finally we will have:

$B=1.17*10^{-8}(8.98*10^{6}x-2.69*10^{15}t)$ (4)

I hope it helps you!

8 0

3 years ago

Which sentence uses a verb incorrectly?

Burka [1]

Answer:

The answer is B).

Explanation:

The correct way to write this sentence is: After I woke up this morning, I got me a tall glass of orange juice.

5 0

3 years ago

g The bottom end of a long vertical tube filled with liquid is opened in a basin exposed to air having pressure 100.8 kilo-Pasca

Masja [62]

Answer:

979.6 kg/m³

Explanation:

We know pressure P = hρg where h = height of liquid = 10.5 m, ρ = density of liquid and g = acceleration due to gravity = 9.8 m/s²

So, density ρ = P/hg

Since P = 100.8 kPa = 100.8 × 10³ Pa

substituting the values of the variables into the equation for ρ, we have

ρ = P/hg

= 100.8 × 10³ Pa ÷ (10.5 m × 9.8 m/s²)

= 100.8 × 10³ Pa ÷ 102.9 m²/s²

= 0.9796 × 10³ kg/m³

= 979.6 kg/m³

So, the density of the liquid is 979.6 kg/m³

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3 years ago

A plane is flying east when it drops some supplies to a designated target below. The supplies land after falling for 10 seconds.

Diano4ka-milaya [45]

solution:

As Given plane is flying in east direction.

It throws back some supplies to designated target.

Time taken by the supply to reach the target =10 seconds

g = Acceleration due to gravity = - 9.8 m/s²[Taken negative as object is falling Downwards]

As we have to find distance from the ground to plane which is given by d.

d = $\frac{1}{2}\times g\times t^2$

= $\frac{1}{2}\times (9.8) \times(100) =50\times 9.8=490$ meters

Distance from the ground where supplies has to be land to plane = Option B =490 meters

6 0

3 years ago

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