Answer:c
Explanation:
The buoyancy force on toy depends upon the volume of toy under pool water.
According to Archimedes principle buoyant force on a floating body depends upon the weight of displaced liquid by object.
Buoyancy force is given by

where
=density of fluid
V=volume of object under water
g=acceleration due to gravity
V^2-u^2=2as
v=final velocity=unkown
u=initial velocity=0 m/s, because freely falling
a=acceleration due to gravity=9.8 m/s^2
s=distance (here height) traveled=4.5m
therefore the final velocity,
v^2=2*9.8*4.5
v=<span>9.39m/s</span>
Remember the definition of work done.
Work done is force(F) times displacement(x)
∴ W = F.Δx
According to Newton's 2nd law of motion,
F = ma
∴ W = ma.Δx ---- (i)
Using the kinematical equation v²-u² = 2ax,
aΔx = (v²-u²)/2
Plug this value in (i),
∴W = m[

]
∴W =

Which is nothing but change in kinetic energy.
That is how kinetic energy is derived
The true airspeed will increase and true altitude will increase.
<h3>
What is true air speed?</h3>
True airspeed is the airspeed of an aircraft relative to undisturbed air.
It's the aircraft speed relative to the airmass in which it's flying.
<h3>How does outside air temperature affect air speed?</h3>
If the outside air temperature increases during a flight at constant power and at a constant indicated altitude, the true airspeed will increase and true altitude will increase.
Thus, the true airspeed will increase and true altitude will increase.
Learn more about true airspeed here: brainly.com/question/13257916
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Answer:
2.82 s
Explanation:
The ball will be subject to the acceleration of gravity which can be considered constant. Therefore we can use the equation for uniformly accelerated movement:
Y(t) = Y0 + Vy0 * t + 1/2 * a * t^2
Y0 is the starting position, 2.3 m in this case.
Vy0 is the starting speed, 13 m/s.
a will be the acceleration of gravity, -9.81 m/s^2, negative because it points down.
Y(t) = 2.3 + 13 * t - 1/2 * 9.81 * t^2
It will reach the ground when Y(t) = 0
0 = 2.3 + 13 * t - 1/2 * 9.81 * t^2
-4.9 * t^2 + 13 * t + 2.3 = 0
Solving this equation electronically gives two results:
t1 = 2.82 s
t2 = -0.17 s
We disregard the negative solution. The ball spends 2.82 seconds in the air.