Answer:
f = 5 cm
Explanation:
using the thin lens equation, given as follows:
where,
f = focal length = ?
do = the distance of object from lens = 20 cm
di = the distance of image from lens = 6.6667 cm
Therefore,
<u>f = 5 cm</u>
Answer:
The colors of the sunset result from a phenomenon called scattering. Molecules and small particles in the atmosphere change the direction of light rays, causing them to scatter. ... The short-wavelength blue and violet are scattered by molecules in the air much more than other colors of the spectrum.
Explanation:
Text book: We can measure the mass of the text book easily by weighing machine, to measure the volume we need to measure the length, width, and height of the text book by the ruler, by multiplying these dimension we can get the volume of the text book, and by dividing the mass of the book with its volume we can get the density of the book.
Milk Container: We can measure the mass of the milk container easily by weighing machine, now (assuming the milk container is cylindrical in shape) we need to measure its height, and and diameter and by the formula (π*r^2*h) we can measure its volume, and and by dividing the mass with its volume we can get the density of the milk container.
Air filled balloon: we can measure the mass of the air filled balloon by weighing it weight machine, we know that the density of air is 28.97 kg/m^3, by dividing the mass of the balloon with the denisty of air we can get the volume of the balloon.
