Answer:
A=
Explanation:
We have given power =40 W but only 10% of this power is used so actual power 
We know that from Stefan's law 
where 
is Boltzmann constant which value is 
So 
A=
Answer: touch the pan to the burner
Explanation:
There are three modes of heat transfer:
conduction, convection and radiation.
For conduction, the heat transfers from a hot object to a cold object when the two are in contact.
For convection there is bulk motion of fluid occurs which transfers the heat.
For heat transfer by radiation, medium is not required.
Thus, to demonstrate conduction between pan and burner, the pan must touch the burner.
Answer:
OD. The process of cutting down irrelevant information so only the information that is useful for particular purpose remains
Answer:
i think it would be B. Aluminum, Al and D. Boron, B
Explanation:
since they're both in group 13 and they forms a 3+ ion
Answer:
6.13 s
219 N
Explanation:
Newton's law in the x direction:
∑F = ma
150 cos 30° N − 50 N = (30 kg) a
a = 2.66 m/s²
Δx = v₀ t + ½ at²
(50 m) = (0 m/s) t + ½ (2.66 m/s²) t²
t = 6.13 s
Newton's law in the y direction:
∑F = ma
Fn + 150 sin 30° N − (30 kg) (9.8 m/s²) = 0
Fn = 219 N
