Answer:
The temperature is
Explanation:
From the question ewe are told that
The rate of heat transferred is
The surface area is
The emissivity of its surface is
Generally, the rate of heat transfer is mathematically represented as
=>
where is the Boltzmann constant with value
substituting value
Answer:
140°
Explanation:
The law of reflection states that the angle of redlection equals to the angle of incidence.
When light rays hit surface at 20°, they also leave the surface at the same angle
Since the whole surface has 180° then subtracting these two angles from total angle gives the the angle between the incident and reflected rays.
180°-20°-20°=140°
The angle of incidence and reflection are equal hence 140/2=70°
The question needed the angle between the incident and reflected rays which is already calculated as 140°
