Answer:
Acceleration = 1.428m/s2
Tension = 102.85N
Explanation:
The detailed solution is attached
Answer:
E = 124.7 N / C
Explanation:
Let's analyze the exercise: the microwave creates an electromagnetic wave of frequency F = 2.45 GHz, this wave is introduced into the microwave cavity and is reflected on the metal walls, which is why one or more standing waves are formed.
The electric field of the standing wave is
I = E²
E =√I
where I is the intensity of the radiation.
What is it
I = P / A
where P is the effective emission power, almost all the power of the microwave and A is the area of the cavity, in the most used microwaves
P = 700 W and the area is A = 25 x 18 cm² = 0.045 m²
I = 700 / 0.045
I = 15555.56 W/m²
let's calculate the electric field
E = √15555.56
E = 124.7 N / C
Answer: velocity of the car is 113.33m/s
Explanation:
From Doppler effect,
in the case which the source is moving towards the observer at rest
f2 = v/(v-vs) *f1
where f2 is the final observed frequency
f1 is the initial observed frequency
v = 340m/s (speed of sound in air)
vs = velocity of the source of sound.
rearranging the above equation
f2*(v - vs) = f1* v
vs = (f1* v/f2) - v
but f1 = 80Hz
f2 = 60Hz
v = 340m/s
substituting,
vs = (80 x 340)/60 - 340
vs = 453.33 - 340
vs = 113.33m/s
velocity of the car is 113.33m/s
