Answer:
The wavelength will be 33.9 cm
Explanation:
Given;
frequency of the wave, F = 1200 Hz
Tension on the wire, T = 800 N
wavelength, λ = 39.1 cm

Where;
F is the frequency of the wave
T is tension on the string
μ is mass per unit length of the string
λ is wavelength

when the tension is decreased to 600 N, that is T₂ = 600 N

Therefore, the wavelength will be 33.9 cm
Answer:
b. horizontal distance/time graph
Explanation:
d is incorrect because object is moving at the same pace the entire time
Answer:
The force required to maintain an object at a constant velocity in free space is equal to Zero.
Answer:
Speed = 0
Restoring force = maximum
Explanation:
Suppose this situation as a spring with a mass attached to it, that oscilates.
The force that the spring does (the restoring force in this case) is something like
F = K*L
where K is the constant of the spring, and L is the difference between the length of the spring (stretched) and the length of the spring at rest.
Then, when the harmonic oscillator is at its maximum displacement, L takes its maximum value, which means that at this point the restoring force must also have a maximum.
And for the velocity, at this point we have the maximum displacement, this means that, if the mass was moving to the right, after this point the mass stops going to the right, and then returns to the equilibrium position to the left.
Then the velocity has a change of sign, (like an object that reached its maximum height) this means that at that exact moment, the velocity must be zero.
Then:
Speed = 0
Restoring force = maximum