It uses microwaves as little heatwaves and uses them to heat the food
The average speed would be 76 km/h. You get this by simply diving the distance by the time.
I think you wrote 4900 twice so will use that as the distance. To solve this it is helpful to draw a picture. The drawing should be of a triangle. Since the driver is driving up at an angle, the 4900 ft will be the hypotenuse of the triangle. since we do not know the values of the other two sides of the triangle we cant solve for the altitude using Pythagorean theorem but we can solve using the sine function on our calculator. As sine of angle is equal to opposite over hypotenuse(sinθ=opposite/hypotenuse). Having θ and the hypotenuse we can solve for opposite or the altitude. using some algebra we get hypotenuse*sinθ=opposite or altitude. now to plug everything in and solve: 4900 ft*(sin(2°))=opposite or altitude=171 ft
(a) frequency of the wave
The electromagnetic wave travels at the speed of light:
. Since its wavelength is
, we can find the frequency of the wave by using the relationship between f,
and c:
(b) magnetic field amplitude
The relationship between the electric field amplitude E, the magnetic field amplitude B and the speed of light c for an electromagnetic wave is
And since we know E, by re-arranging the equation we can find the magnitude of B: