The results of the calculation are;
a) The feet spends 0.41 s in air
b) The highest point above board is 2.62 m
c) The velocity when her feet hit the water is 7.2 m/s
<h3>What is the time spent in air?</h3>
From the data presented;
v = u + at
But v = 0 m/s at the maximum height thus;
0 = 4 - (9.8 * t)
4 = 9.8 * t
t = 4/9.8
t = 0.41 s
b) from;
h = ut - 1/2gt^2
h = (4 * 0.41) - (0.5 * 9.8 * (0.41)^2)
h = 1.64 - 0.82
h = 0.82 m
The total height above board = 0.82 m + 1.8 m = 2.62 m
c) The total time in air is obtained from;
h = ut + 1/2gt^2
u = 0m/s because she dropped off the board
h = 1/2gt^2
2.62 = 0.5 * 9.8 * t^2
t = √2.62/0.5 * 9.8
t = 0.73 seconds
Hence, the velocity when her feet hit the water is obtained from;
v = u + gt
when u = 0 m/s
v = gt
v = 9.8 * 0.73 s
v = 7.2 m/s
Learn more about velocity:brainly.com/question/13303224
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