If astronomers watch the stars all night, they have to keep moving their telescopes as the stars seem to move across the sky. Why does this happen?

Dao makes a table to identify the variables used in the equations for centripetal acceleration. what quantities belong in cells x and y?

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?

The goal of this experiment was to answer the question, "how does diffraction occur? " suppose you formulated this alternate hypothesis: if the gap width is increased while keeping wavelength constant, then the observed diffraction will decrease because the less the ratio between wavelength and gap width is, the smaller the observed diffraction angle will be.to test this hypothesis, you would change the  gap widthdiffraction anglewavelength  and observe the  gap widthdiffraction anglewavelength  in the system.therefore, the independent variable would be the  gap widthdiffraction anglewavelength  and the dependent variable would be the  gap widthdiffraction anglewavelength.