Hey!
NOTE-:
u= initial velocity
v= final velocity
g= acceleration due to gravity
t= time
u= 0
v= 49 m/s
t=?
g= 9.8 m/s^2
Using first equation of motion -
v-u=at
49-0= 9.8×t
49 = 9.8t
49/9.8= t
t= 5 second
Hope it helps...!!!
Tin is Sn, atomic number 47 is Silver, Mass of sodium is 22.9 u
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
Depends on how well built he is probably for the average American 8 MPH
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