In this case the coordinate z is multiplied by your wave vector k, so it travels along z. Note that the electric field will be oscillating along the x direction. H and E are perpendicular to the direction of travel in vacuum.
Answer:
C. 1.50×10¹¹ m
Explanation:
First, convert the time to seconds.
8 min × (60 s/min) + 20 s = 500 s
Distance = speed × time
d = (3×10⁸ m/s) (500 s)
d = 1.50×10¹¹ m
Answer:
F = 20.4 i ^
Explanation:
This exercise can be solved using the ratio of momentum and amount of movement.
I = F t = Dp
Since force and amount of movement are vector quantities, each axis must be worked separately.
X axis
Let's look for speed
cos 45 = vₓ / v
vₓ = v cos 45
vₓ = 8 cos 45
vₓ = 5,657 m / s
We write the moment
Before the crash p₀ = m vₓ
After the shock 
= -m vₓ
The variation of the moment Δp = mvₓ - (-mvₓ) = 2 m vₓ
The impulse on the x axis Fₓ t = Δp
Fₓ = 2 m vₓ / t
Fx = 2 0.450 5.657 / 0.250
Fx = 20.4 N
We perform the same calculation on the y axis
sin 45 = vy / v
vy = v sin 45
vy = 8 sin 45
vy = 5,657 m / s
We calculate the initial momentum po = m 
Final moment = m
Variations moment Δp = m - m = 0
Force in the Y-axis 
= 0
Therefore the total force is
F = fx i ^ + Fyj ^
F = Fx i ^
F = 20.4 i ^
vf = vi + at
vf – vi = at<span>
<span>vi= 0, vf=26 and afor nil = 9.8m/s2</span></span>
26 = 9.8t
t =<span> 26 / 9.8 = 2.65 s
Now we know the total time, so we can calculate the time 1
second before it hit the ground.
<span>= 2.65 -1 = 1.65s
<span>Now again using the same equation, vf = vi+at, we can find vf
vi = 0, a = 9.8 t=1.65</span></span></span>
vf = 0 + 9.8(1.65) =
16.17 m/s<span>
</span><span>So,
the nail is traveling with the speed of 16.17m/s 1 second before it hits the
ground.</span>
What we have so far:
*Distance you walked the dog = 0.75 miles
*Conversion: 1 mile is approximately 1.61 kilometers
What we are trying to find:
*Distance you walked the dog in kilometers.
To solve this problem we must:
*We must employ conversion first.
Step 1) 0.75miles x 1.61km/1miles <--- Multiplication will be employed.
Step 2) 0.75 x 1.61/1 (km)<--- notice that we deleted the unit "miles". We did that to make sure that the result will be in kilometers (km).
Step 3) 0.75 x 1.61(km) <--- Since we are already done with the conversion process, we now have to multiply the distance and the conversion factor.
Step 4) 1.2075km <--- Raw result.
Step 5) Rounding it up to two decimal places: 1.21km
Therefore, the correct answer is: D. 1.21km
