Explanation:
Given that,
An object in free fall will fall d feet in t seconds, where d and t are related by the algebraic model as :
..........(1)
(a) We need to find the time taken by the object to fall 1148 ft. Put this in equation (1) as :


t = 8.47 seconds
(b) If the object is in free fall for 18.5 sec after it is dropped, then the height of the object is given by :

d = 5476 ft
Hence, this is the required solution.
C
<span>Write at least 20 characters to explain it well.</span>
Answer:
(a) 
(b) 
(c) 
Solution:
As per the question:
Mass of Earth, 
Mass of Moon, 
Mass of Sun, 
Distance between the earth and the moon, 
Distance between the earth and the sun, 
Distance between the sun and the moon, 
Now,
We know that the gravitational force between two bodies of mass m and m' separated by a distance 'r' is given y:
(1)
Now,
(a) The force exerted by the Sun on the Moon is given by eqn (1):



(b) The force exerted by the Earth on the Moon is given by eqn (1):



(c) The force exerted by the Sun on the Earth is given by eqn (1):



Answer:
The change in the mechanical energy of the projectile is 43,750 J
Explanation:
Given;
mass of the projectile, m = 5 kg
initial velocity of the projectile, u = 200 m/s
final velocity of the projectile, v = 150 m/s
The change in mechanical energy is calculated from the principle of conservation of energy;
ΔP.E = ΔK.E
The change in potential energy is zero (0)
0 = ΔK.E
ΔK.E = K.E₁ - K.E₂
ΔK.E = ¹/₂mu² - ¹/₂mv²
ΔK.E = ¹/₂m(u² - v²)
ΔK.E = ¹/₂ x 5(200² - 150²)
ΔK.E = 43,750 J
Therefore, the change in the mechanical energy of the projectile is 43,750 J