We know that the change in momentum is equals to the product of force and time that is impulse (
). Therefore, we need to determine the value of that the water is in air by using the second equation of motion,

Here, u is initial velocity which is zero.
.
Thus, impulse

From Newton`s second law,

Therefore, impulse

Given,
and 
Substituting these values, we get
Change in momentum = impulse
.
Answer:
60.025m.
Explanation:
S= ut + at^2/2 (2nd equation of motion)
S= 0 + (9.8)(3.5)^2 /2 (free fall case, initial velocity = 0)
S = 4.9 x 12.25
S= 60.025 m.
Disclaimer: did math in my head, so you better double check with a calculator.
Answer:
1.997s = 2.0s
Explanation:
From equation of motion,
S = ut + 1/2 gt²
u = 0 m/s
t = ?
g = 9.8 m/s²
S = 1955cm = 19.55m
19.55 = 0 + 1/2 * 9.8 * t²
19.55 * 2 = 9.8t²
t² = 19.55 * 2 / 9.8
t² = 3.987
t = (3.987)^½ (take the square root of both sides)
t = 1.997s = 2.0s