Problem 1- At the distance of Earth, 147 million kilometers, what is the angular diameter of the sun whose physical diameter is 1.4 million kilometers? Problem 2 - At the distance of closest approach to the solar surface Solar Probe Plus will be at a distance of 5.8 million kilometers from the solar surface. What will be the angular diameter of the sun if its physical diameter is 1.4 million kilometers? Problem 3 - A DVD disk measures 12 cm in diameter. How far from your eyes will you have to hold the DVD disk in order for it to subtend the same angular size as the disk of the sun viewed by Solar Probe Plus at its closest distance?

47 PHYS 40.0 cm 20.0 cm 80.0 cm Figure shows uniform solid cylinder 80.0 cm long and 40.0 cm in diameter, with a small spherical portion removed from it. The diameter of this removed portion is 20.0 cm and its center is 20.0 cm from one end of the cylinder. Find the center of gravity of the remaining portion if the center of the sphere lies on the axis of the cylinder. Formula: Vsphere = (pid^3)/6; Vcylinder = (pid^2h)/4; (Vcyl - Vsphere) xcg = (Vcyl xcyl – Vsphere xsphere) %3D

4. 51 Pegasi b was the first extra-solar planet found around a main sequence starother than our Sun. The star, 51 Pegasi, is very much like the Sun, and it has a luminosityL = 1.30L⊙. 51 Pegasi b has an average orbital radius of 0.0527 AU and it is tidally lockedto 51 Pegasi. Given that it thought to have a Bond albedo of 0.1, what is its “no greenhouse”temperature? Note- it is tidally locked, but you should assume the temperature of the planetis uniform due to winds transferring heat.

These images show one of the large `VLT’ telescopes at the European Southern Observatory’s facility at Cerro Paranal, Chile. The place where the laser beam comes out (seen in the inset photo) is just out of sight off of the top edge of the large photo. Also note that if you look down the telescope tube (in the main photo), you can see the tube’s front-end structure. Why is there a laser beam shooting out of the front of this telescope (in the inset picture)? Group of answer choices The beam creates an `artificial star’, which is used by an adaptive-optics system to measure (and counteract) the blurring effect of Earth’s atmosphere. The astronomers are bouncing light off of objects near the center of the Milky Way galaxy, to measure their distances from Earth. The astronomers are taking pictures of the surface of a planet (most likely Mars), and the laser allows them to light up the planet’s surface with a very specific color of light. The astronomers are engaged in the opening…