Answer:
The answer is 34.67 kilograms force
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
Here is just a few:
1. white guys cant jump like black guys therefore white guys shouldn't play basketball
2. men are stronger than women so men should weight lift
3.football is a manly sport therefore woman should not play it
*hope this helps(these are just examples I am not expressing my beliefs
They believe the distortions happened when two galaxies collided.
Hope This Helps :)