Cousin throckmorton is playing with the clothesline. one end of the clothesline is attached to a vertical post. throcky holds the other end loosely in his hand, so that the speed of waves on the clothesline is a relatively slow 0.740m/s . he finds several frequencies at which he can oscillate his end of the clothesline so that a light clothespin 43.0cm from the post doesn't move. what are these frequencies?