Answer:
A) Greater than the attraction between two small objects the same distance apart.
Explanation:
The gravitational force between two objects is:
F = GMm / r²
where G is the gravitational constant,
M is the mass of one object,
m is the mass of the other object,
and r is the distance between the objects.
If the distance is the same, then two large objects will have a larger gravitational force between them than two small objects.
Answer:
Explanation:
Use the equation

where h(t) is the height after a certain amount of time goes by, v0t is the initial upwards velocity, and h0 is the initial height of the projectile. For us:
h(t) = 10
v0t = 80
h0 = 3 and filling in:
and get everything on one side to factor:

This factors to
t = .09 sec and 4.9 sec. Let's interpret this.
The time of .09 is when the ball reached 10 feet on the way up, and
the time of 4.9 is when the ball reached 10 feet on the way back down. That's the height we need, 4.9 seconds.
The amount of work done on the weights would be approximately 15.0 Kg of work