If the speed of a wave is 50 m/s and the period of time between waves is 2 seconds. what is the frequency?

Freya has a mass of 14kg she is running at 1.1m/s to the left when she runs into eric, who is standing still. eric has a mass of 18kg. after the collision, they continue moving together. what is their velocity after the collision. a. 0.48 m/s to the leftb. 2.5 m/s to the leftc. 0.86 m/s to the leftd. 1.4 m/s to the left