The answer to this question is D
For this, all you need is the velocity formula which is Vf = Vi + at.
Vf = final velocity.
Vi = initial velocity.
a = acceleration
t = time
Vf = Vi + at.
Vf= 0 + (-<span> 9.8 m/sec^</span><span>2) (7s)
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*The 0 says that the original velocity is zero. The - 9.8 m/sec^2 is gravity because there is nothing else acting upon it, and it is negative because it is falling. The 7s is time time.*
All you have to do then, is simplify to get 68.6 m/s which is B.
Well 4 just means that there are 4 of these things. so 1/2 is also the same as 50/100 or 25/50 or 500/1000 (the gist of it) so you just multiply the bottom and the top by the same number which would just give you different improper fractions