Answer:
Initial velocity = 
b) Height it reaches = 44.145 m
Explanation:
Using the first equation of motion we have
here
v is the final velocity
u is the initial velocity
a is the acceleration of the object
t is time
When the ball reaches it's highest point it's velocity will become 0 as it will travel no further
Also the acceleration in our case is acceleration due to gravity (
) as the ball moves in it's influence alone with '-' indicating downward direction
Thus applying the values we get
b)
By 3rd equation of motion we have
here s is the distance covered
Applying the value of u that we calculated we get
Light travels at a speed of:
The distance between Mercury and Sun is
, so the time it takes is
if we want to convert this into minutes, keeping in mind that 1 min = 60 seconds, we should divide this value by 60:
Answer:
W = 47040 J
Explanation:
Given that,
The mass of a student, m = 60 kg
Height of the tower, h = 80 m
We need to find the work done in climbing the tower. The work done is given by :
W = mgh
So,
W = 60 × 9.8 × 80
W = 47040 J
So, the required work done is 47040 J.
Answer:
Explanation:
Galileo proved the superiority of the heliocentric theory over the geocentric theory . Heliocentric theory changed the centre of universe from the earth to the sun . According to this theory , the solar system or the universe revolves around the sun .
But the present knowledge of universe considers sun as one of billions of stars present in the universe , with each star behaving as sun with its own solar system . The universe is made of cluster of stars with each cluster having their own centre around with they revolve . These clusters are called galaxy . Sun is a part of cluster called milky way . Sun along with other star of this galaxy revolves around the centre of its galaxy which is a super massive star .
Hence the old heliocentric theory does not fit into the present framework of universe by the scientist.
