The water manometer above is measuring the pressure of gas supply. if the specific gravity of mercury is 13.6 and the atmospheric pressure is 70cm of mercury what is the total pressure of the gas supply in cm of water
in the image above, an incident ray XY makes an angle of 15\( ^{\circ} \) with a fixed line AY which is normal to surface of a plane mirror if the mirroe is turned as indicated by the arrow through \( 40^{\circ} \) what angle will the reflected ray make with AY
