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3 years ago

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Add the following numbers, using scientific notation and the correct amount of significant digits. 3.4⋅10 8m + 4.56⋅10 9m = ____

_.
A 4.9 ⋅10 9m
B 4.9 ⋅10 8m
C 7.96 ⋅10 9m
D 7.96 ⋅10 8m

2 answers:

Gnoma [55]3 years ago

7 0

The answer is B
<span>B 4.9 ⋅10 8m
</span>

Artist 52 [7]3 years ago

5 0

Answer:

The answer is A) 4.9 × 10^9

Explanation:

I literally just did the calculation, the other dude is wrong.

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Meteor Infrasound A meteor that explodes in the atmosphere creates infrasound waves that can travel multiple times around the gl

kherson [118]

Answer:

0.04455 Hz

Explanation:

Parameters given:

Wavelength, λ = 6.5km = 6500m

Distance travelled by the wave, x = 8830km = 8830000m

Time taken, t = 8.47hours = 8.47 * 3600 = 30492 secs

First, we find the speed of the wave:

Speed, v = distance/time = x/t

v = 8830000/30492 = 289.58 m/s

Frequency, f, is given as velocity divided by wavelength:

f = v/λ

f = 289.58/6500

f = 0.04455 Hz

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3 years ago

Although the evidence is weak, there has been concern in recent years over possible health effects from the magnetic fields gene

Natasha2012 [34]

Answer:

A. $B = 6.36 * 10^{-10} T$

B. P ≈ 0

Explanation:

In order to calculate the magnetic field strength we have to use the magnetic field strength of a straight wire.

$B = \frac{mi* I}{2\pi *d}$ (eq. I)

B = magnetic field strength at distance d

I = current (A)

mi = represented by the greek letter μ, represents the permeability of the free space, which is: 4 × π 10^(-7) T m/A

d = distance from the wire

By replacing the values in eq I, we have the following:

$B = \frac{4\pi 10^{-7} T m A^{-1} 200 A}{2\pi *20 m}\\\\B = 6.36 * 10^{-10} T\\$ (eq II)

The earth magnetic field in the surface variates from 25 to 65 microteslas. Thus:

P = Percentage from the wires/percentage of the earth

$P = \frac{6.36 * 10^{-10}T}{65* 10^{-3} T}\\$ ∵ $B$ ∴

P ≈ 0

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4 years ago

Why is it important for a scientist to be open-minded but skeptical?

insens350 [35]

It’s important for a scientist to be open-minded because they need to be able to understand or creative anything that was never thought about. It’s also important for a scientist to be skeptical because some ideas or products that they hear about can have false factors. I hope this helped!

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3 years ago

Read 2 more answers

Find the momentum (in kg.m/s) of a helium nucleus having a mass of 6.68 x 10^-27 kg that is moving at 0.386c.

igomit [66]

Answer:

$7.73544\times 10^{-21}kgm/sec$

Explanation:

We have given mass of helium nucleus $m=6.68\times 10^{-27}kg$

Velocity of helium nucleus $v=0.386c=0.386\times 3\times 10^{8}m/sec=1.158\times 10^{8}m/sec$

Momentum of the helium nucleus is given by $P=mv$ where m is mass and v is velocity

So $P=mv=6.68\times 10^{-27}\times 1.158\times 10^{8}=7.73544\times 10^{-21}kgm/sec$

6 0

3 years ago

To protect their young in the nest, peregrine falcons will fly into birds of prey (such as ravens) at high speed. In one such ep

I am Lyosha [343]

Answer:

Part a)

$\theta = 48 degree$

Part b)

$v = 13.45 m/s$

Explanation:

Part a)

mass of the Falcon bird is given as

$m = 600 g$

initial speed of the bird is

$v_i = 20 m/s$

final speed of the bird is given as

$v_f = 5 m/s$ (opposite direction)

So here the impulse given by falcon bird is given as

$I = m(v_f - v_i)$

$I = 0.600(20 + 5)$

$I = 15 kg m/s$

now the final momentum of Raven bird in perpendicular direction is given as

$I = mv_y$

$15 = 1.50 v_y$

$v_y = 10 m/s$

now the change in the angle of the raven bird is given as

$tan\theta = \frac{v_y}{v_x}$

$tan\theta = \frac{10}{9}$

$\theta = 48 degree$

Part b)

Final speed of the raven bird is given as

$v^2 = v_x^2 + v_y^2$

$v^2 = 9^2 + 10^2$

$v = 13.45 m/s$

5 0

3 years ago