Why does a siren have a higher pitch as it approaches you?

The amplitude of the sound wave is increased.

The crests of the sound wave are spaced closer together.

The troughs of the sound wave are farther apart.

The period of the sound wave is increased.

Aball has an initial velocity of 3 m/s. if there is no friction, what is the highest it could roll?

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

Often called simply "velocity," this is the velocity of an object at a particular moment in time.