The heat and energy of coal burning is more easier and more efficient to turn into electricity than any method using renewable resources.
F = G*((m sub 1*m sub 2)/r^2)
I think you almost got it.
At the top, the velocity only has horizontal component, so v=12 m/s is v_x, which is v*cos(theta), because v_x is constant, so the same when it was launched or now.
With the value of the initial speed (28 m/s, which is the total speed), you can set
v_x = v * cos( theta ) ---> 12 = 28*cos(theta) --> cos(theta)=12/28=3/7
or theta = 64.62 deg, it is D. Think about it. I hope you see it.
As the plane falls the parabolic path remains directly below as the plane continues to fly over. This give more of an overview. When the package falls vertical acceleration happens as there is a vertical velocity as the package falls form high above. The downwards motion of gravity acts on the package if the approximated projectile motion ignoring air resistance.
Answer:
The sponge must go 
deep
Explanation:
If F = 6360 N, then it is required to find how deep can an object with this force hitting on a sponge get.
We know that, F = mgh
m is mass
g is acceleration due to gravity
So, the sponge must go deep.
