Answer:

Explanation:
For sound waves we have v=d/t where v is the speed of sound and d the distance between the astronauts, while for electromagnetic waves we have c=D/t where c is the speed of light and D the distance between the spaceship and Earth. <em>We have written both times as the same</em> because is what is imposed by the problem, so we have t=d/v=D/c, which means:

And for our values:

Answer:
a) v = 6.43 m/s
b) v = 15.8 m/s
Explanation:
Speed of car = 56 km/h
56 km/h = 14.4 m/s
Angle rain makes on the glass to the vertical = 66°
Thus knowing that the opposite side of the angle is the distance moved by the car, and the adjacent side is the distance traveled by the rain in the same time
both of which are directly proportional to their velocities
Then
tan(66°) = 14.44m/s ÷ x
or x = 14.44/tan(66°)
Which is the vertical raindrop velocity of the relative to earth
v = 6.43 m/s vertically towards earth
For v relative to the car is we have vector sum of both velocities
v = √(14.44^2 + 6.43^2) = 15.8 m/s which is the velocity relative to car
= 15.8 m/s
For part a)
Since the conical surface is not exposed to the radiation coming from the walls only from the circular plate and assuming steady state, the temperature of the conical surface is also equal to the temperature of the circular plate. T2 = 600 K
For part b)
To maintain the temperature of the circular plate, the power required would be calculated using:
Q = Aσ(T₁⁴ - Tw⁴)
Q = π(500x10^-3)²/4 (5.67x10^-8)(600⁴ - 300⁴)
Q = 5410.65 W
Increasing the pressure of gas is like exactly the same as increasing its concentration. If you have a given mass of gas, the way you increase its pressure is to squeeze it into a smaller volume.
Hope this helps!