Well first of all, a planet doesn't have a semimajor axis, although it's orbit does.
In an orbit with a smaller semimajor axis, the planet moves faster, and its orbital period is shorter.
That's why the International Space Station circles the Earth in less time than the Moon does.
One of the equations of gravity is this:

Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up)
h = height of object
Substitute for the values and you should have something like this



Answer:
C.
would adapt if the dress were held completely still
Explanation:
Answer:
2s
Explanation:
Given parameters:
Distance = 30m
Speed = 15m/s
Unknown:
Time before Laurence caught it = ?
Solution:
To solve this problem;
Speed =
Time taken =
=
= 2s
The time it takes is 2s
A field is the description of a spatial region, the force exerted on objects by a field is a field force.
gravitational force field: surrounds every material object, although only objects planet-sized or larger exert significant gravity.
electric force field: surrounds and affect electrical charges
magnetic force field: surround magnets and materials with electricity flowing through them. magnetic fields affect susceptible materials such as iron or other magnets.
hope i helped a little