Answer:
<em>Choice: c. 6sec</em>
Explanation:
<u>Horizontal Launch
</u>
When an object is thrown horizontally with a speed (v) from a height (h), it describes a curved path ruled by gravity until it finally hits the ground.
The horizontal component of the velocity is always constant because no acceleration exists in that direction, thus:

The vertical component of the velocity changes in time because gravity makes the object fall at increasing speed given by:

Where 
To calculate the time the object takes to hit the ground, we use the same formula as for free-fall, since the time does not depend on the initial speed:

The marble rolls the edge of the table at a height of h=180 m, thus:


t = 6 sec
Choice: c. 6sec
Refraction occurs when a wave enters a new medium and changes its speed.
i hope this helps
Answer:
The acceleration of a 1000 kg car subject to a 550 N net force = 0.55 m/s^2
Explanation:
Given:
F = 550 N
m = 1000 kg
To Find:
a = ?
Solution:
So by the equation by Newton's 2nd Law of Motion,
F = m x a
550 N = 1000 kg x a
a = 550 N/ 1000 kg
a = 0.55 m/s^2
Therefore,
The acceleration of a 1000 kg car subject to a 550 N net force = 0.55 m/s^2
PLEASE MARK ME AS BRAINLIEST!!!
Answer:
2. You must be able to precisely measure variations in the star's brightness with time.
5. As seen from Earth, the planet's orbit must be seen nearly edge–on (in the plane of our line-of-sight).
6. You must repeatedly obtain spectra of the star that the planet orbits.
Explanation:
The transit method is a very important and effective tool for discovering new exoplanets (the planets orbiting other stars out of the solar system). In this method the stars are observed for a long duration. When the exoplanet will cross in front of theses stars as seen from Earth, the brightness of the star will dip. To observe this dip following conditions must be met:
1. The orbit of the planet should be co-planar with the plane of our line of sight. Then only its transition can be observed.
2. The brightness of the star must be observed precisely as the period of transit can be less than a second as seen from Earth. Also the dip in brightness depends on the size of the planet. If the planet is not that big the intensity dip will be very less.
3. The spectrum of the star needs to be studied and observe during the transit and normally to find out the details about the planets.
4. Also, the orbital period should be less than the period of observation for the transit to occur at least once.
It is a reflecting telescope and a compound microscope. I know this for sure