just need the explanation of how 1.5wavelengths = 4.5 which means the wavelength is 3? like Im confused.. the other tutor never answered me back so, yea. (answer question a)

A mechanical oscillator makes waves in a string as shown in the diagram. An observer notices that it takes 0.50 s for the waves to travel a distance of 3.0 m. 4.5 m Complete the questions that follow. a) Find the wavelength in metres. (2 marks) b) Find the speed of the wave. (2 marks) c) What would happen to the speed of the wave and the wavelength if the frequency of the source were changed to 2.5 Hz? (2 marks) a) 0.25 b) 6m/s c) wavelength = 1.2 , speed = 3m/s This question has not been graded. The correct answer is not displayed for Written Response type questions. Hide question 4 feedback a) 1.51 = 4.5 m X = (4.5 m)/1.5 A = 3.0m (2 marks) - D A 3.0 m 0.5 s v = 1.5 m/ s (2 marks) c) The speed will not change and the wavelength will decrease to 1.5 m. (2 marks)