Which are advantages of reflecting telescopes? check all that apply.

there is no rainbow-like halo around the image.

reflecting telescopes can be made very large. reflecting telescopes use only lenses, not mirrors.

only the reflecting side of the primary mirror needs to be perfectly shaped and smooth.

the eyepiece creates an image for the observer.

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?