Yes spoon can sound like a bell. To prove this, we perform an experiment.The handle of the spoon is tied at the mid point of the string, then wrap the ends of the string around pointer fingers. Now place fingers in ears. Lean over so that spoon hangs freely and swing the spoon so it taps against a door.
A sound is produced because the spoon vibrated, causing sound waves to travel up the string and into ears.
Answer:
For destructive interference phase difference is
where n∈ Whole numbers
Explanation:
For sinusoidal wave the interference affects the resultant intensity of the waves.
In the given example we have two waves interfering at a phase difference of
would lead to a constructive interference giving maximum amplitude at at the RMS value of the amplitude in resultant.
Also the effect is same as having a phase difference of
because after each 2π the waves repeat itself.
<em>In case of destructive interference the waves will be out of phase i.e. the amplitude vectors will be equally opposite in the direction at the same place on the same time as shown in figure.</em>
They have a phase difference of
or which is same as 
Generalizing to:
a phase difference of
where n∈ {W}
{W}= set of whole numbers.
Answer:
Zero
Explanation:
It is given that,
A person swims to the other end of a 20m long pool and back.
We need to find his displacement.
Displacement = shortest path covered
He reaches at the same position as from where he has started. It means the shortest path covered is equal to 0 i.e. his displacement is zero.
Answer:

Explanation:
given,
s = 400- 16 t²
we know,
Velocity of an object is defined as the change in displacement per unit change in time.
velocity an also be return as




Hence, instantaneous velocity function given by 
To calculate instantaneous velocity, you need to insert value of time.
ex, instantaneous velocity at t = 4 s
v = -32 x 4 = -128 m/s.
A). Both the energy and the wave travel in the same direction.
If they didn't, they'd wind up in different cities almost instantly.