
Bradford T. answered 05/02/23
Retired Engineer / Upper level math instructor
The quadratic regression for mercury
h(t) = -6t2+87t+31 = at2/2+v0t+h0
which would make the hill 31 feet high.
Also hearth(t) = -16t2+87t+31
If you use the quadratic formula to solve for t for h(t)=0, t=5.7731 ≈ 5.8 seconds
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If you don't want to do regression, you can use the first two data points to solve for v and h
-6+v+h = 112
-24+2v+h = 181
Subtracting the first equation from the second gives
-18+v=69 ==> v=87
-6+87+h=112 ==> h =31
Same answer