Answer:
70.07 Hz
Explanation:
Since the sound is moving away from the observer then
and
when moving towards observer
With of 76 then taking speed in air as 343 m/s we have
Similarly, with of 65 we have
Now
v_s=27.76 m/s
Substituting the above into any of the first two equations then we obtain
Answer:
e. Object X has traveled four times as far as object Y.
Explanation:
The distance covered by an object in uniform accelerated motion is given by:
where
u is the initial velocity
t is the time
a is the acceleration
The two objects in the problem have same initial velocity, u = 0 (since they start from rest), so we can rewrite the equation as
We see that the distance covered is proportional to the square of the time. In this problem, the two objects X and Y have same acceleration, but object X accelerates for twice the time: since , this means that the distance covered by X will be
times higher that the distance covered by object Y.