55 J
Explanation:
Kinetic energy is given as: 0.5MV^2 where M is the mass and V is the speed of rotation. Since the masses are point masses, we calculate the point mass for each mass.
M1 = 30*0.2^2 = 1.2kgm^2
M2 = 20*0.4^2 = 3.2kgm^2
V = 5 rad/s
Calculating using the formula above, we obtain :
0.5(1.2+3.2)5^2 =0.5*4.4*25 = 55 J
Explanation:
spectral lines or signatures of elements depend on temperature, the temperature of the sun is about 5800 K.
at this temperature most calcium atoms are excited to higher energy states than hydrogen atoms and this means that calcium atoms are gonna have more signatures than the atoms of hydrogen.
the statement that the sun shows weak hyrogen lines and strong calcium line is wrong because at the sun's temperature most of the hydrogen atoms are in lower energy states while calcium atoms are in higher energy states hence calcium has more or ''strong'' lines than hydrogen.
I believe it is, since the heat causes the water to evaporate and cause condensation,
Answer:
7.468 kN
Explanation:
Here the force is given in Newton
Some of the prefixes of the SI units are
kilo = 10³
Mega = 10⁶
Giga = 10⁹
Tera = 10¹²
The number is 7468.0
Here, the only solution where the number of significant figures is kilo. If any other prefix is chosen then the significant figures will increase.
1 kilonewton = 1000 Newton
So, 7468 N = 7.468 kN
Angle, θ2 at which the light leaves mirror 2 is 56°
<u>Explanation:</u>
Given-
θ1 = 64°
So, α will also be 64°
According to the figure:
α + β = 90°
So,
β = 90° - α
= 90° - 64°
= 26°
β + γ + 120° = 180°
γ = 180° - 120° - β
γ = 180° - 120° - 26°
γ = 34°
γ + δ = 90°
δ = 90° - γ
δ = 90° - 34°
δ = 56°
According to the law of reflection,
angle of incidence = angle of reflection
θ2 = δ = 56°
Therefore, angle θ2 at which the light leaves mirror 2 is 56°
