A 2.40 kg stone is sliding in the +r-direction on a horizontal,
frictionless surface. It collides with a 4.00 kg stone at rest. After the col-
lision the 2.40 kg stone is moving at 3.60 m/s at an angle of 30.0" mea-
sured from the +x-direction toward the +y-direction, and the 4.00 kg
stone is moving at an angle of 45.0 measured from the +x-direction
toward the-y-direction. (a) What is the y-component of momentum of
the 2.40 kg stone after the collision? What must be the y-component
of momentum of the 4.00 kg stone after the collision? (b) What is the
speed of the 4.00 kg stone after the collision? (c) What is the x-component
of the total momentum of the two stones after the collision? (d) What is
the speed of the 2.40 kg stone before the collision?

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