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!
<span>rocky surface
(outer plants are made of gas)</span>
If the machine is 100% efficient, then its
Mechanical Advantage is (450/50) = 9 .
If the machine is less than 100% efficient,
then the MA is more than 9 .
Answer:
B . energy cannot be created or destroyed