A Red Rider bb gun uses the energy in a compressed spring to provide the kinetic energy for propelling a small pellet of mass 0.27 grams. By cocking the lever attached to the stock of the rifle, the spring (k = 1900 N/m) is compressed 9.5 cm from its equilibrium point. 1. What is the potential energy energy stored in the compressed spring?
2. What is the kinetic energy of the pellet when the spring is released?
3. What is the muzzle velocity of the bb?
4. If the rifle was modified so that the spring could be compressed twice as far, 19 cm, what would be the resultant muzzle velocity of the bb?

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