Question

1. A vibrating point on a spring travels 60 mm during three cycles. What is the amplitude of the vibration?
a) 0.05 mm
b) 5.0 mm
c) 15.mm
d) 20.mm
e) 180 mm
my answer: I got 10 mm but it is not listed as an option

Answer 1

three cycles, or 20mm pre cycle. Amplitude is 10mm, or 1 cm.

I am wondering what they mean by three cycles? I agreed with you . However, sometimes common folks think cycle is just one passing, not two, so if that were the case, it would have traveled 1.5 waves, or 60/1.5=40mm back and forth, or 20 mm amplitude.