Answer:
The acceleration of the satellite is 
Explanation:
The acceleration in a circular motion is defined as:
(1)
Where a is the centripetal acceleration, v the velocity and r is the radius.
The equation of the orbital velocity is defined as
(2)
Where r is the radius and T is the period
For this particular case, the radius will be the sum of the high of the satellite (
) and the Earth radius (
) :


Then, equation 2 can be used:
⇒ 


Finally equation 1 can be used:

Hence, the acceleration of the satellite is 
Specific heat. The definition of specific heat is the amount of energy required to raise the temperature of 1g of a substance by 1K or 1°C.
What you need to know is that the force is
F=ma
The force is the product of mass and acceleration
this means that the acceleration is
a=F/m
a) The force is halved?
this means that f will be

now:
a=

So the accelaration will also he halved (it's the original acceleratation divided by 2)
b) The object's mass is halved?
a=

=a=

which is the original acceleration times two!! so it will double
c) The force and the object's mass are both halved?
now we have
a=

=a=

=a=

so they will cancel each other out and the acceleration will stay the same!
Technically this is a Biology question;
The 'amount' we can see depends on how much light can get through our pupil to hit our retina.
When there is a lot of light the pupil is small; it doesn't need to be big to let a lot of light in.
When we move to a dark space there is much less light, so the pupil 'dilates' to let enough light so we can see properly.
The period in which one cant see is simply when the pupil hasn't had time to change shape yet so doesn't let in enough light.<span />