An intensity of 1.0 x 10^-1 W/m² can cause damage to the ears. If the power of sound from a rock band's amplifier is 85 W, how far are you standing from the speaker if you are damaging your ears?

Aspring is used to stop a 50-kg package which is moving down a 20º incline. the spring has a constant k = 30 kn/m and is held by cables so that it is initially compressed 50 mm. knowing that the velocity of the package is 2 m/s when it is 8 m from the spring and neglecting friction, determine the maximum additional deformation of the spring in bringing the package to rest.