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3 years ago

1. Question

1 answer:

6 0

All of the forces listed are correct. There are 4 presently known forces.
Second question os B. the Lorentz force. It's given by
F=q(E+VxB) where q is the electric charge, E is the electric field, V is the particle's velocity vector, B is the magnetic flux density, and "x" represents the vector cross product.

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In the reaction _S+302 +2SO3, what coefficient should be placed in front of the S to balance the reaction?

lys-0071 [83]

Answer:

B. 2

Explanation:

The reaction expression is given as:

_S + 3O₂ → 2SO₃

Now let us balanced the expression;

On the product side we have 2 moles of S

On the reactant side we should have 2moles of S

So, we put the coefficient 2 to balance the expression;

We have 6 moles oxygen on both sides

5 0

3 years ago

I NEED HELP!!!!!!!!!!!

nadezda [96]

1. 168.1 Hz

To find the apparent frequency heard by the driver in the car, we can use the formula for the Doppler effect:

$f'=(\frac{v\pm v_o}{v\pm v_s})f$

where

f is the original sound of the horn

v is the speed of sound

$v_o$ is the velocity of the observer (the driver and the car), which is positive if the observer is moving towards the source and negative if it is moving away

$v_s$ is the velocity of the sound source (the train), which is positive if the source is moving away from the observer and negative otherwise

In this problem we have, according to the sign convention used:

$v = 343 m/s\\f = 164 Hz\\v_o = -15 m/s\\v_s = -23 m/s$

Substituting, we find:

$f'=(\frac{343-15}{343-23})(164)=168.1 Hz$

2. $2.96\cdot 10^8 m/s$

The speed of light can be calculated as

$v=\frac{d}{t}$

where

d is the distance travelled

t is the time taken

In this problem:

$d=2\cdot 3.85\cdot 10^8 =7.7\cdot 10^8 m$ is the total distance travelled by the laser beam (twice the distance between the Earth and the Moon)

t = 2.60 s is the time taken

Substituting in the formula,

$v=\frac{7.7\cdot 10^8 m}{2.60 s}=2.96\cdot 10^8 m/s$

6 0

3 years ago

A physical property is a characteristic of a substance is one that _____.

Korolek [52]

A is the correct answer !!!

4 0

3 years ago

An initially uncharged 3.47-μF capacitor and a 6.43-kΩ resistor are connected in series to a 1.50-V battery that has negligible

harkovskaia [24]

Answer: a) io=233.28 A ( initial current); b) τ=R*C= 22.31 ms; c) 81.7 ms

Explanation: In order to explain this problem we have to use, the formule for the variation of the current in a RC circuit:

I(t)=io*Exp(-t/τ)

and also we consider that io=V/R=(1.5/6.43*10^3)

=233.28 A

then the time constant for the RC circuit is τ=R*C=6.43*10^3*3.47*10^-6

=22.31 ms

Finally the time to reduce the current to 2.57% of its initial value is obtained from:

I(t)=io*Exp(-t/τ) for I(t)/io=0.0257=Exp(-t/τ) then

ln(0.0257)*τ =-t

t=-ln(0.0257)*τ=81.68 ms

3 0

3 years ago

Two airplanes leave an airport at the same time. The velocity of the first airplane is 730 m/h at a heading of 65.3 ◦ . The velo

yanalaym [24]

Answer:

Plane will 741.6959 m apart after 1.7 hour

Explanation:

We have given time = 1.7 hr

So if we draw the vectors of a 2d graph we see that the difference in angles is = $102^{\circ}-65.3^{\circ}=36.7^{\circ}$

Speed of first plane = 730 m/h

So distance traveled by first plane = 730×1.7 = 1241 m

Speed of second plane = 590 m/hr

So distance traveled by second plane = 590×1.7 = 1003 m

We represent these distances as two sides of the triangle, and the distance between the planes as the side opposing the angle 58.6.

Using the law of cosine, $r^2$ representing the distance between the planes, we see that:

$r^2=1241^2+1003^2-2\times 1003\times 1241cos(36.7)=550112.8295$

r = 741.6959 m

3 0

3 years ago