Answer:

Explanation:
Close to Earth's surface, the force of gravity that pulls an object towards the ground is
(2)
where
m is the mass of the object
g is the acceleration due to gravity, which is
close to Earth's surface
This is an approximation of the general formula of gravity valid only close to Earth's surface. The more general formula is
(1)
where
G is the gravitational constant
M is the Earth's mass
m is the object's mass
r is the distance of the object from Earth's center
At the Earth's surface,
r = R (Earth's radius), and by calling the following factor

we see that eq.(1) becomes eq.(2).
Question 1.
- mass = 4500 kg
- potential energy (p.e) = 67500 J
now, we know :
=》

=》

=》

=》

=》

note : if we take acceleration due to gravity as 9.8, then height = 1.53 m
Question 2.
- mass = 4500 kg
- kinetic energy = 63000 j
we know,
=》

=》

=》

=》

=》

=》

or
=》

True. That is how powerful the sun is. But it will explode in only about 5 billion years.
The particles always move parallel and perpendicular to the waves. The waves which are in the water moves a circle. Both up and down and back and forth.
Good luck :)
Answer:
The velocity of the ball before it hits the ground is 381.2 m/s
Explanation:
Given;
time taken to reach the ground, t = 38.9 s
The height of fall is given by;
h = ¹/₂gt²
h = ¹/₂(9.8)(38.9)²
h = 7414.73 m
The velocity of the ball before it hits the ground is given as;
v² = u² + 2gh
where;
u is the initial velocity of the on the root = 0
v is the final velocity of the ball before it hits the ground
v² = 2gh
v = √2gh
v = √(2 x 9.8 x 7414.73 )
v = 381.2 m/s
Therefore, the velocity of the ball before it hits the ground is 381.2 m/s