A, chemical bondings would yield a positive enthalpy change, thus endothermic.
Answer:
As the tines of the tuning fork vibrate at their own natural frequency, they created sound waves that impinge upon the opening of the resonance tube. These impinging sound waves produced by the tuning fork force air inside of the resonance tube to vibrate at the same frequency.
Answer:

Explanation:
Let at any moment of time the friend's car is at some horizontal distance "x" from the position of balloon.
Now if the altitude of the balloon is fixed and it is at height "h"
so here we will have

now we know that
initially the angle of the friend's car is 35 degree
so the horizontal distance will be

similarly if the angle after passing the car position is 36 degree
then we have

now the speed of the balloon is constant
so we have




so the final position of friend when the angle is 36 degree


Answer:
216 m
Explanation:
Assuming a straight line:
Δx = vt
Δx = (12 m/s) (18 s)
Δx = 216 m