From page 15 we learn furthermore
y(t)
= v0yt
- gt2/2
Hence, at the instant τ
we have in the case of the golf ball
h = y(τ)
= v0τ
- gτ2/2
= v0(v0/g)
- g(v0/g)2/2
= v02/2g
which leaves us with
v02
= 2gh
With h=3.07±0.15 m
and
g=9.8 m/s2,
Walter Lewin arrives for the initial value of the velocity at
v02
= 2 ( 9.8 m/s2 ) ×
( 3.07±0.15 m )
= 60.2±2.9 m2/s2
He does not calculate v0, because the future formulas only involve
the square of v0.
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