The answer is voluntary involvement! :D Welcome
Answer:
Explanation:
Amount of heat required can be found from the following relation
Q = mcΔT
m is mass of the body , c is specific heat and ΔTis rise in temperature .
Here m = 300 kg
c = 3350 J /kg k
ΔT = 30 - 25
= 5 °C
Putting the values in the expression above
Q = 300 x 3350 x 5
= 5025000 J
Rate at which energy is absorbed = 1200 J /s
Time required
= 5025000 / 1200
= 4187.5 S
= 69.8 minute
= 1 hour 9.8 mimutes.
Explanation:
I believe part of the question is missing. can you please check on it?
is there a part where the mass of the object is mentioned?
Answer:
Spontaneous emission is a quantum effect, which in a semiclassical picture can be described as an emission which is stimulated by vacuum noise.
Answer:
40°
Explanation:
when a ray light is incident on a surface it makes a 40° angle with the normal to the surface (reflecting surface ). this called angle of incidence.
And the angle made by reflected ray with the normal to the surface is called angle of reflection.
by the law of reflection angle of incidence is equal to the angle of reflection
hence the answer to the question is 40° ( because ∠i =∠r )