The answer should be C. :)
Answer:
The force between two objects is calculated through the equation,
F = Gm₁m₂/d²
where m₁ and m₂ are the masses of the objects. In this case, an unknown mass and Earth. d is the distance between them and G is the universal gravitation constant.
In the second case, if the force is to become 2.5 times the original and all the variables are constant except d then,
2.5F = Gm₁m₂ / (D²)
D = 0.623d
Subsituting the known value of d,
D = 0.623(6.9 x 10^8) = 4.298 x 10^8 m
Answer:
The change of the momentum of the ball is 
Explanation:
We should find 
(1)with 
the initial momentum and 
the final momentum. Linear momentum is defined as 
, using that on (1):
(2)
It's important to note that momentum and velocity are vectors and direction matters, so if +x direction is the direction towards the wall and the -x direction away the wall 
and 
so (2) becomes:
F=ma
a=(v2-v1)/(t2-t1)
a=(6-0)/(12-0)
a=6/12
a= .5 m/s^2
f=2300kg*.5m/s^2
f=1150N
f=1200N if using correct sig figs
