Answer:
t=4.86s
Explanation:
To find the wavelength you use the following formula:

v: speed of sound = 343m/s
f: frequency = 400Hz
λ: wavelength of the sound
By doing λ the subject of the formula and replacing the values of f and v you obtain:

Now, to calculate the time that sound takes to reach the last row you use:

t: time
d: distance to the last row = 1947m

hence, the time is 4.86s
Addition of 2vector gives you 1large vector quantity
Answer:
9.6
Explanation:
to convert km to miles multiply by 1.609
dude is -2m/s, ...ettte is +2m/s
pos vel is when dudette, eg, is going in increasing x, in this case.
neg vel is when dudette, eg, is going in decreasing x, in this case. ie she turns round and runs
zero vel is zero speed. dudette standing still
positive vel neg pos top dia
no
yes
yes
yes
yes
yes
all yes looks like ...