You have been called in by your neighborhood safety council to advise them about installing a barrier on a dangerous curve that has been subject to several recent accidents. They need to decide between a new a "softer barrier", which consists of barrels of water, and the traditional concrete barrier. In a test, two 1400 kg cars initially travelling at 50 mph were crashed into each barrier. The softer barrier took 1.6 s to bring the car to a rest, while the traditional barrier took 0.1. You have been asked to prepare a report on the force exerted on the car in each case.

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

Adisk with a radius of r is oriented with its normal unit vector at an angle q with respect to a uniform electric field. which of the following would result in an increase in the electric flux through the disk? check all that apply? a. increasing the area of the disk b. decreasing the given orientation angle of the disk c. decreasing the strength of the electric field d. increasing the given orientation angle of the disk, but not exceeding an angle of 90

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