Answer:. Option c
Explanation: the speed of an electromagnetic wave is simply the vector product of the magnetic field and the electric field.
The direction of the velocity is the direction of the electromagnetic wave.
The wave is already moving towards the negative y axis (-j) and the magnetic field is already pointing towards the positive x axis (i)
From cross product of unit vectors
i × j = k
i × k = - j
With the second identity, we can see that the electric field will be pointing towards the positive of the x axis (k).
Option c is validated
Answer:
The magnetic flux through the desk surface is 
.
Explanation:
Given that,
Magnetic field B = 0.42 T
Angle =68°
We need to calculate the magnetic flux
Where, B = magnetic field
A = area
Put the value into the formula
Hence, The magnetic flux through the desk surface is .
Answer:
a. 8.96 m/s b. 1.81 m
Explanation:
Here is the complete question.
a) A long jumper leaves the ground at 45° above the horizontal and lands 8.2 m away.
What is her "takeoff" speed v
0
?
b) Now she is out on a hike and comes to the left bank of a river. There is no bridge and the right bank is 10.0 m away horizontally and 2.5 m, vertically below.
If she long jumps from the edge of the left bank at 45° with the speed calculated in part a), how long, or short, of the opposite bank will she land?
a. Since she lands 8.2 m away and leaves at an angle of 45 above the horizontal, this is a case of projectile motion. We calculate the takeoff speed v₀ from R = v₀²sin2θ/g. where R = range = 8.2 m.
So, v₀ = √gR/sin2θ = √9.8 × 8.2/sin(2×45) = √80.36/sin90 = √80.36 = 8.96 m/s.
b. We use R = v₀²sin2θ/g to calculate how long or short of the opposite bank she will land. With v₀ = 8.96 m/s and θ = 45
R = 8.96²sin(2 × 45)/9.8 = 80.2816/9.8 = 8.192 m.
So she land 8.192 m away from her bank. The distance away from the opposite bank she lands is 10 - 8.192 m = 1.808 m ≅ 1.81 m
Memorize this and you'll be able to do ALL of these: <em>1 kg = 1,000 g</em>
So if you have some grams, divide the number by 1,000 to get kilograms.
1,000 g = 1.000 kg
500 g = 0.500 kg
100 g = 0.100 kg
50 g = 0.050 kg
20 g = 0.020 kg
10 g = 0.010 kg
