Answer:
The time taken for the ball to fly up in the air and back down again is 3.058 seconds.
Explanation:
Since the ball ends up at the same vertical distance ( on the ground) as it was at the start of its motion, we can set the total displacement of the ball equal to 0.
Thus, this problem can be simply solved by the following equation of motion:
Here, s = total change in distance = 0 m
u = initial speed = 15 m/s
a = acceleration due to gravity = -9.81 m/s^2
t = time (to be found)
Substituting these values in the equation we get:
t = 3.058 seconds
So, the time taken for the ball to fly up in the air and back down again is 3.058 seconds.
1. Light Travelling from denser medium to less dense medium
2. Light Travelling from less dense medium to denser medium
Explanation :
Edwin Hubble used a telescope to discover the movement of galaxies in 1929. He was an American Astronomer.
The telescope invented by him is called a Hubble telescope. It has a 2.4-meter mirror.
He gives the relation between the distance to a galaxy and its recessional velocity. This is known as the Hubble law. The relation is as follows :
where,
is recessional velocity.
is Hubble constant.
is distance.
<em>So, the given statement is True.</em>
The changes in celsius are the same as those in kelvins. the difference between the two scales is that 0 celsius is about 273 kelvins and that 0 kelvins is about -273 celsius (note the minus sign)
