
Actually Welcome to the Concept of the Wave Optics.
Whenever the waves are out of phase they form a DESTRUCTIVE interference.
thus,
Destructive Interference occurs when two waves are out of phase.
Power = work/time
= 500/10
= 50J/s or 50 watt
Answer:
8 mph
Explanation:
4 miles in half hour so you add 4 more for the second half
d = distance traveled by her on her bicycle on a long flat road = 24 kilometer
t = time taken by her to travel distance "d" on her bicycle on a long flat road = 1.2 hours
v = average speed of vivian = ?
we know that average speed is given as
v = d/t
inserting the values in the above formula
v = 24 kilometer / 1.2 hour
v = 20 kilometer/hour
hence the correct choice is
C) 20 km/h
Roughly 13.8 billion years old according to science