A guitar string transmits waves at 509 m/s. To create a 491 Hz note, to what length should the guitar player shorten the string? (Unit = m)​

i think it’s a. this is because if they measured the mass of something with a mass of 150g, then their final answer would have to be approximately 150g. though all of their answers are almost 150, rosa and tran have the closest answers (or the exact answer) to the accurate one.

it about 600 mph from what i calculated

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

neither accurate nor precise.