Answer:
t_{out} =
t_{in}, t_{out} = 
Explanation:
This in a relative velocity exercise in one dimension,
let's start with the swimmer going downstream
its speed is

The subscripts are s for the swimmer, r for the river and g for the Earth
with the velocity constant we can use the relations of uniform motion
= D / 
D = v_{sg1} t_{out}
now let's analyze when the swimmer turns around and returns to the starting point

= D / 
D = v_{sg 2} t_{in}
with the distance is the same we can equalize

t_{out} = t_{in}
t_{out} =
t_{in}
This must be the answer since the return time is known. If you want to delete this time
t_{in}= D / 
we substitute
t_{out} = \frac{v_s - v_r}{v_s+v_r} ()
t_{out} = 
You need to provide a picture or tell us the examples... we can’t see what you see
Explanation:
<em>The height of the pendulum is measured from the lowest point it reaches (point 3). </em>
At 1, the kinetic energy of the pendulum is zero (because it is not moving), and it has maximum potential energy.
At 2, the pendulum has both kinetic and potential energy, and how much of each it has depends on its height—smaller the height greater the kinetic energy and lower the potential energy.
At 3, the height is zero; therefore, the pendulum has no potential energy, and has maximum kinetic energy.
At 4, the pendulum again gains potential energy as it climbs back up, Again how much of each forms of energy it has depends on its height.
At 5, the maximum height is reached again; therefore, the pendulum has maximum potential energy and no kinetic energy.
Hope this helps :)