A stationary source S generates circular outgoing waves on a lake. The wave speed is 4.0 m/s and the crest-to-crest distance is 80 cm. A boat is approaching the source at 1.0 m/s. The frequency of these waves, as observed by a person in the boat, is

Which statements about tornadoes are true? check all that apply. (a) about 12,000 tornadoes hit the united states every year. (b) a tornado looks like a funnel. (c) tornadoes are deadly atmospheric storms that cause millions in damages each year. (d) tornadoes can reach wind speeds of more than 300 miles per hour. (e) kansas is the state with the most tornadoes. (f) you will always notice a funnel before a tornado strikes.

Which of the following is the phase that results when the moon is on the opposite side of the earth from the sun? a. quarter moon b. crescent moon c. new moon d. full moon

Suppose you plot the distance traveled by an object at various times and you discover that the graph is not a straight line. what does this indicate about the object's acceleration?