Ablock of mass m1 = 2.0 kg slides along a frictionless table with a velocity of +10 m/s. directly in front of it, and moving with a velocity of +3.0 m/s, is a block of mass m2 = 6.0 kg.

a massless spring with spring constant k = 1120 n/m is attached to the second block as in the figure below.(a) before m1 runs into the spring, what is the velocity of the center of mass of the system? ? m/s(b) after the collision, the spring is compressed by a maximum amount δx. what is the value of δx? ? cm(c) the blocks will eventually separate again. what is the final velocity of each block measured in the reference frame of the table?

Achild has maximum walking speed of 1.6 m/s. what is the length of the child's legs? 0.26 m

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

Match the words or actions and their definition. 1. the rate of doing work 2. a machine that changes motion 3. the force that is used to generate electricity 4. 550 foot-pounds per second 5. the force that makes things fall toward the earth 6. work in > work out 7. metric measurement of work 8. the product of force times distance water falling from a dam newton-meter gravity work windmill power the work principle 1 horsepower