Waves Assist please.?

Plans marimba marimba bar: question by Hilary R .? Waves please support A marimba (name of instrument) from a set of wooden slats that type a keyboard. Each and every bar is held in place by two screws. If a bar is struck with a mallet, it vibrates in a standing wave with two nodes and 3 antinodes. The lowest frequency is 87. Hz, note that from a beam, is .400m extended wird.a) What is the wavelength of the standing wave? B) What is the speed of transverse waves on the bar? C) The sound

How to make a marimba