Answer it's 1,445 A
Explanation:
Basically 9,875 - what will give you 8,430 that's what's its asking. Its just a gap.
Answer:9.75 m/s
Explanation:
Given
Length of ladder 
Foot the ladder is moving away with speed of 
From diagram
------1
at 


Now differentiating equation 1 w.r.t time




negative indicates distance is decreasing with time
Hope this answer helps, cause Idk, I might be wrong, but I still, I used the correct formulas, so I might be correct
It is situated in period number 1.