The answer is d! I’m happy to help :)
Answer: 8Ω
Explanation:
Since there are two resistors of 4Ω
connected in series, the total resistance (Rtotal) of the circuit is the sum of each resistance.
i.e Rtotal = R1 + R2
R1 = 4Ω
R2 = 4Ω
Rtotal = ?
Rtotal = 4Ω + 4Ω
Rtotal = 8Ω
Thus, the total resistance of the circuit is 8Ω
Assuming north as positive direction, the initial and final velocities of the ball are:

(with negative sign since it is due south)

the time taken is

, so the average acceleration of the ball is given by

And the positive sign tells us the direction of the acceleration is north.
Answer:
88.8 m/s= Speed of wave propagation in the required mode.(3 loops)
Explanation:
When there are 3 loops.
the total length = L = 3 λ /2
⇒ λ = 2 L / 3 = 2 ( 1.11 ) / 3 = 0.74 m
Velocity = v = f λ = (120)(0.74) = 88.8 m/s