If a scientist is studying a model that is a widely accepted theory about the position of planets and sun, the model would most likely help the scientist to understand facts that can't be easily observed. That will make the correct answer to be C.
Answer:
y = 0.99 m
Explanation:
This is a projectile launching exercise, let's start by finding the components of the initial velocity, using trigonometry
cos θ = v₀ₓ / v₀
sin θ = v_{oy} / v₀
v₀ₓ = vo cos θ
v_{oy} = I go sin θ
v₀ₓ = 15 cos 30 = 12.99 m / s
v_{oy} = 15 sin 30 = 7.5 m / s
Let's find the time it takes to travel x = 18 m
x = v₀ₓ t
t = x / v₀ₓ
t = 18 / 12.99
t = 1,385 s
at this point it is at a height of
y = v_{oy} - ½ g t²
y = 7.5 1.385 - ½ 9.8 1.385²
y = 0.99 m
therefore the camera must place the foot 99 cm from the ground
To solve this problem we will apply the theorem given in the conservation of energy, by which we have that it is conserved and that in terms of potential and kinetic energy, in their initial moment they must be equal to the final potential and kinetic energy. This is,


Replacing the 5100MJ for satellite as initial potential energy, 4200MJ for initial kinetic energy and 5700MJ for final potential energy we have that



Therefore the final kinetic energy is 3600MJ