On Earth, the period of a pendulum is given by:
where L is the length of the pendulum and
is the gravitational acceleration on Earth.
Similarly, the period of the same pendulum on Mars will be
where
is the gravitational acceleration on Mars.
Therefore, if we want to see how does the period of the pendulum on Mars change compared to the one on Earth, we can do the ratio between the two of them:
Therefore, the period of the pendulum on Mars will be 1.63 times the period on Earth.
As a reference, consider the line from the point perpendicular to the mirror.
That direction is called 'normal' to the mirror.
The ray on the right leaves the point traveling 5° to the right of the normal,
and leaves the mirror on a path that's 10° to the right of the normal.
The ray on the left leaves the point traveling 5° to the left of the normal,
and leaves the mirror on a path that's 10° to the left of the normal.
The angle between the two rays after they leave the mirror is 20° .
Frankly, Charlotte, if there were more than 5 points available for this answer,
I'd seriously consider giving you a drawing too.
This has to do with Doppler effect. If the source or the observer moves, they the observer will hear a different frequency. Since the source is stationary, we only need to know whether the observer is moving.
Since Observer A does not hear a change in frequency, he a must be stationary. So we can ignore C and D
Since Observer B hears a different frequency, Observer B must be moving. Here's the tricky part. We need to find whether B is moving towards or away the source. Since he hears a lower frequency, he is walking away from the source. So the answer is A.
You can conform with the Doppler equation.
Answer: A
Those materials insulate(keep out heat),thus making the house cool
The correct answer for that question would be. A
