This is called a Rube Goldberg device. It attempts to perform a simple task through a complex series of steps. Most of the time, what is used for each step? A) solar cells
B) simple machines
C) complex machines
D) plants and animals

What would the difference of spectral lines emitted by hydrogen gas in distant galaxies which is normally found at a wavelength of 21 cm on earth, be observed at 21.1 centimeters?

Find the mass by adding the numbers from the three sliders

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?