Answer: C) 200 N
Explanation:
The force
is defined as:

Where:
is the mass of the object
is the acceleration
Then:

Finally:

Hence, the correct option is C.
Good afternoon.
We have:

The function of velocity:

For
t = 5 s:
Answer:
Single replacement
Explanation:
A reaction in which one element replaces a similar element is called single replacement. In this case, C is replacing A.
Answer: Looked it up but
Explanation:
When the skater lands on the track, the vertical component of his kinetic energy is converted to thermal energy. You can do experiments where there is no loss to thermal energy (only PE and KE conversions) by turning friction off and by making sure the skater doesn't leave the track.