Benda setinggi 3 cm diletakkan pada jarak 10 cm di depan cermin cekung yang berjari-jari
kelengkungan 10 cm. Tentukan:
 Jarak bayangan
 Perbesaran bayangan
 Sifat bayangan

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b. refraction c. diffraction d. interference

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.

Estimate of the number of stars in our galaxy