The spectrum of light from the moon should very strongly resemble the spectrum of sunlight. The reason is that any light from the moon started out from the sun. Any difference in their spectra is only due to the moon absorbing more of some wavelengths and less of others. But since the moon appears colorless gray, we don't expect any particular colors to be strongly absorbed, otherwise the moon would look to be the colors of the light that's left.

3 0

3 years ago

Arigid body must rotate about an axis in order for it to have angular momentum about that axis. True False

kompoz [17]

Answer:

False

Explanation:

Let's consider the definition of the angular momentum,

$\vec{L} = I \vec{\omega}$

where $I = \int\limits_m r^2 dm = \lim_{n \to \infty} \sum\limits_{i=1}^n m_i r_i^2$ is the moment of inertia for a rigid body. Now, this moment of inertia could change if we change the axis of rotation, because "r" is defined as the distance between the puntual mass and the nearest point on the axis of rotation, but still it's going to have some value. On the other hand,

$\vec{\omega} = \frac{\vec{r} \times \vec{v}}{r^2}$ so $\vec{\omega} \neq 0$ unless $\vec{r}$ ║ $\vec{v}$ .

In conclusion, a rigid body could rotate about certain axis, generating an angular momentum, but if you choose another axis, there could be some parts of the rigid body rotating around the new axis, especially if there is a projection of the old axis in the new one.

7 0

2 years ago

Which order shows decreasing momentum?

klio [65]

Answer:

Explanation: Decreasing in velocity

4 0

3 years ago

What type of charge is acquired when a rubber is rubbed with a fur

Rus_ich [418]

Answer:

The triboelectic charging process (a.k.a., charging by friction) results in a transfer of electrons between the two objects that are rubbed together. Rubber has a much greater attraction for electrons than animal fur.

Explanation:

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4 0

2 years ago