Answer:
In an electromagnetic wave in free space, the ratio of the magnitudes of electric and magnetic field vectors E and B is equal: <u>speed of light(c) </u>
Explanation:
Generally the ratio of the E(electric field ) and the B(magnetic field ) is equal to the speed of the electromagnetic wave i.e the speed of light (c) the value is

Actually a black board has all colours in light or white light . So when light falls on it board absorbs all colours because all are present so no light is reflected back. That is the case, and so it will appear black as it absorbs all colours of light that fall on it .
Answer:
9.75 km
Explanation:
Charlie runs 6.5 km/hr
-> Charlie wants to run for 1.5 hours
6.5km + 6.5km/2
= 6.5 km + 3.25km
= 9.75 km
Answer:
magnitude = 304.14 km/h
direction:
West of North
Explanation:
The final plane's vector velocity will be the result of the vector addition of one pointing North of length 300 km/h, another one pointing West of length 50 km/h.
To find the magnitude of the final velocity vector (speed) we need to apply the Pythagorean theorem in a right angle triangle with sides: 300 and 50, and find its hypotenuse:
km/h
The actual direction of the plane is calculated using trigonometry, in particular with the arctan function, since the tangent of the angle can be written as:

So the resultant velocity vector of the plane has magnitude = 304.14 km/h,
and it points
West of the North direction.