If swimmers had a choice of the water slides shown in this figure,
they would all go home dry, since there is no figure. I'll have to try to
answer this question based on only the words in the text, augmented
only by my training, education, life experience, and human logic.
-- Both slides are frictionless. So no energy is lost as a swimsuit
scrapes along the track, and the swimmer's kinetic energy at the
bottom is equal to the potential energy he had at the top.
-- Both slides start from the same height. So the same swimmer
has the same potential energy at the top of either one, and therefore
the same kinetic energy at the bottom of either one.
-- So the difference in the speeds of two different swimmers
on the slides depends only on the difference in the swimmers'
mass, and is not influenced by the shape or length of the slides
(as long as the slides remain frictionless).
If both swimmers have the same mass, then v₁ = v₂ .
To develop this problem it is necessary to apply the concepts related to Wavelength, The relationship between speed, voltage and linear density as well as frequency. By definition the speed as a function of the tension and the linear density is given by

Where,
T = Tension
Linear density
Our data are given by
Tension , T = 70 N
Linear density , 
Amplitude , A = 7 cm = 0.07 m
Period , t = 0.35 s
Replacing our values,



Speed can also be expressed as

Re-arrange to find \lambda

Where,
f = Frequency,
Which is also described in function of the Period as,



Therefore replacing to find 


Therefore the wavelength of the waves created in the string is 3.49m
According to Newton's Second Law of Motion :
The Force acting on an Object is equal to Product of Mass of the Object and Acceleration produced due to the Force.
Force acting = Mass of the Object × Acceleration
Given : Force = 50 newton and Mass of the Object = 10 kg
Substituting the respective values in the Formula, we get :
50 N = 10 kg × Acceleration

Acceleration of the Object = 5 m/s²
If they both are moving with the same speed and direction
i.e. covering the same distance in the same time interval in the same direction
The longer you continue to listen, the more beats will be heard.
They'll occur at the rate of (260Hz - 254Hz) = 6 Hz .