Answer:
2160.26 N.
Explanation:
From the question,
The total energy of the woman = work done by the water.
mg(h+d) = F'×d.......................... Equation 1
m = mass of the the woman, g= acceleration due to gravity, h = height of the platform, d = depth of water reached by the woman, F'= Resistance force exerted on her by the water.
make F' the subject of the equation
F' = mg(h+d)/d............................ Equation 2
Given: m = 65.0 kg, g = 9.8 m/s², h = 11 m, d = 4.6 m.
Substitute into equation 2
F' = 65(9.8)(11+4.6)/4.6
F' = 9937.2/4.6
F' = 2160.26 N.
Answer:
a) 31.4 m/s
b) 50.2 m
Explanation:
a) When an object is free falling, its speed is determined by the gravity force giving it acceleration. Equation for the velocity of free fall started from the rest is:
v = g • t
g - is gravitational acceleration which is 9.81 m/s^2, sometimes rounded to 10
t - is the time of free fall
So:
v = 9.81 m/s^2 • 3.2
v = 31.4 m/s ( if g is rounded to 10, then the velocity is 10 • 3.2 = 32 m/s)
b) To determine the distance crossed in free fall we use the equation:
s = v0 + gt^2/2
v0 - is the starting velocity (since object started fall from rest, its v0 is 0)
s = gt^2/2
s = 9.81 m/s^2 • 3.2^2 / 2
s = 50.2 m (if we round g to 10 then the distance is 10 • 3.2^2/2 = 51.2 meters)
Answer:
Straight line parallel to time axis.
Explanation:
The slope of the position time graph gives the velocity.
As the man is still, that means the velocity is zero. So, the slope of the graph is zero. It is a straight line parallel to time axis.
Kinetic energy = 1/2 * mass * velocity^2
In this case,
KE = 1/2 * 1569 kg * (15 (m/s))^2 = 176,5 kN
