Answer:
(c). The two blocks end in a tie
Explanation:
the reason being the absence of any resistance offered to both of the blocks.
if the slope of the hill is for instance 60 deg.
then the acceleration in absence of any resistance is a= 9.81sin(60)
since the acceleration is same then both of the blocks will reach at the same instant
Answer:
d' = 75.1 cm
Explanation:
It is given that,
The actual depth of a shallow pool is, d = 1 m
We need to find the apparent depth of the water in the pool. Let it is equal to d'.
We know that the refractive index is also defined as the ratio of real depth to the apparent depth. Let the refractive index of water is 1.33. So,

or
d' = 75.1 cm
So, the apparent depth is 75.1 cm.
Answer:
First Quarter and Third Quarter.
Explanation:
Tides are formed as a consequence of the differentiation of gravity due to the Moon across to the Earth sphere.
Since gravity variates with the distance:
(1)
Where m1 and m2 are the masses of the two objects that are interacting and r is the distance between them.
For example, seeing the image below, point A is closer to the Moon than point b, and at the same time the center of mass of the Earth will feel more attracted to the Moon than point B. Therefore, that creates a tidal bulge in point A and point B.
When the Sun and the Moon are alight with respect to the Earth, then the Sun tidal force contributes to the tidal force of the Moon over the Earth. That makes the high tides even higher (spring tides).
However, when the Sun is not in the same line than the Moon (the Moon is at 90° with respect to the Sun), then the low tides are higher and the high tides are lower. That scenario is known as neap tides.
Therefore, that happens when the Moon is at First Quarter and Third Quarter.