A thimble 3.3 cm high is 17.0 cm from a concave mirror. the radius of the curvature of the mirror is 12.0 cm. How far from the mirror is the image and is it real ot virtual?

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?

The frequency of a tuning fork can be found by the method shown. a long tube open at both ends is submerged in a beaker of water, and the vibrating tuning fork is placed near the top of the tube. the length l of the air column is adjusted by moving the tube vertically. the sound waves generated by the fork are reinforced when the length of the air column corresponds to one of the resonant frequencies of the tube. the smallest value for l for which a peak occurs in sound intensity is 7 cm. l what is the frequency of the tuning fork? the speed of sound in air is 345 m/s. answer in units of hz

Pl i beg u so much now propane burns in oxygen to produce carbon dioxide and steam. the unbalanced equation for this reaction is: c3h8 + o2 → co2 + h2o use coefficients to balance this equation. a) c3h8 + 3 o2 → 3 co2 + 4 h2o b) c3h8 + o2 → 3 co2 + 4 h2o c) c3h8 + 5 o2 → 3 co2 + 4 h2o d) 2 c3h8 + 5 o2 → 3 co2 + 4 h2o