Answer:
Amplitude of F = 0 cm
Step-by-step explanation:
We know that both waves have same amplitude. Note that when two waves are out of phase, algebraic sum of two waves is calculated.
So,
Amplitude of F = Amplitude of D + Amplitude of E
Supposing amplitude of D is upwards in direction and amplitude of E is downwards in direction.
Amplitude of F = 2 + (-2)
Amplitude of F = 0 cm