Answer:
632.8 nm is the wavelength (in air) of red light from a helium neon laser.
Explanation:
The gravitational force equation is the following:

Where:
G = Gravitational constant = 
m1 & m2 = the mass of two related objects
r = distance between the two related objects
The problem gives you everything you need to plug into the formula, except for the gravitational constant. Let me know if you need further clarification.
Answer:
a
Explanation:
it has no more water to make it bigger
The crate would slide forward