Consider the following statements. Two are true. Which one is false? The frequency of a vibrating object refers to the average speed with which the object moves over the course of a vibration.
The frequency of a vibrating object refers to the number of complete cycles of vibrations made per unit of time.
The frequency of a vibrating object refers to how often a vibrating object repeats its vibration.

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s