The spaceship Lilac, based on the Purple Planet, is 721 m long when measured at rest. When the Lilac passes Earth, observers there measure its length to be 661 m. At what speed v is the Lilac moving with respect to Earth? Express your answer as a multiple of the speed of light c.

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? ab c d

What is the largest meteoroid that has collided with this planet