Question

In the activity on page 131,What will happen if you lift one of the tubes to some height​

Answer 1

If you were to lift an object above the ground at a constant speed, you would have to exert a force of equal magnitude and opposite the direction of gravity onto it. However, wouldn't these forces cancel out and thus not affect the object's position at all? Also, if this object was elevated at a constant speed, I understand that it would gain in gravitational potential energy since its height above the ground is increasing. But what about its kinetic energy? Although there is no net force in the direction of the object's motion (constant speed, so equilibrium), the object is still moving, so wouldn't it possess some amount of kinetic energy? If so, what becomes of it once the object stops at some height, h?

Answer 2

Answer:

(a) If one of the tubes is lifted, angle of incidence will not be equal to angle of reflection, hence, the sound will not be clearly audible.

(b) Angle of incidence is same as the angle of reflection.