At what angle will 630-nm light produce a second-order maximum when falling on a grating whose slits are 1.55×10^–3 cm apart? (b) how many number of slits per cm does this grating have? (c) draw a diagram indicating the 1st and 2nd order bright fringes.

Galileo was the first to notice that the moon has craters, valleys, and mountains. how might this have changed people's perception of the moon at the time?

Amass attached to a spring is displaced from its equilibrium position by 5cm and released. the system then oscillates in simple harmonic motion with a period of 1s. if that same mass–spring system is displaced from equilibrium by 10cm instead, what will its period be in this case? a mass attached to a spring is displaced from its equilibrium position by and released. the system then oscillates in simple harmonic motion with a period of . if that same mass–spring system is displaced from equilibrium by instead, what will its period be in this case? a) 0.5sb) 2sc) 1sd) 1.4s

Suppose astronomers built a 140-meter telescope. how much greater would its light-collecting area be than that of the 10-meter keck telescope? express your answer using two sign