- The school zone in front of your school has a posted speed limit of 25 mi/h, which is about 11 m/s. Let's examine the stopping of a car in several different situations.
a. The crossing guard holds up her stop sign, and the driver is paying attention well. The car moves at a
constant velocity of 11 m/s for 2.3 seconds while the driver reacts, then slows down at a constant rate
of -4.5 m/s2. What is the stopping distance for the car in this situation?

1. what is the relationship between wavelength and the penetrating power of an electromagnetic wave? a) the penetrating power has no relationship to the wavelength. b) the penetrating power increases as the wavelength increases. c) the penetrating power decreases as the wavelength increases. d) the penetrating power decreases as the wavelength decreases. 2. as ice melts and turns into water, the speed of sound through the material would most likely do what? justify your answer. a) the speed would not change because the material is always water. b) the speed of sound would increase because the density of water is less than that of ice. c) the speed of sound would increase because energy is added to ice in order to make it melt. d) the speed of sound would decrease because sound travels faster through solids than liquids. 3.which of these waves need a medium to travel through? a) sound b) x-rays c) infrared rays d) visible light