Answer:
<span>GPE=81000J or 81kJ</span>
Explanation
Potential Energy = mgh = 20 x 9.8 x ?
<span>To find H use one of the equation of motion </span>
<span>= [(90)^2 - 0 ] / 2(9.8) </span>
<span>Potential Energy = mgh = 20 x 9.8 x 8100 /2(9.8) = 81000 J</span>
if in 1 second the jet goes 428 meters and you want to know how long it takes to go 237 meters you just divide 237/428
it can be written like this
_1_ = __x__
428 237
cross multiply
428 times x = 1 times 237
428x=237
divide by 428 on both sides
x= 237/428
x=0.5537 seconds
