Answer:
Work = power * time
time = 20000 joules / 1000 joules / sec = 20 sec
Because the charges of static electricity and the eons coming from your hair pull together to make the balloon stick
Answer:
finding Cepheid variable and measuring their periods.
Explanation:
This method is called finding Cepheid variable and measuring their periods.
Cepheid variable is actually a type of star that has a radial pulsation having a varying brightness and diameter. This change in brightness is very well defined having a period and amplitude.
A potent clear link between the luminosity and pulsation period of a Cepheid variable developed Cepheids as an important determinants of cosmic criteria for scaling galactic and extra galactic distances. Henrietta Swan Leavitt revealed this robust feature of conventional Cepheid in 1908 after observing thousands of variable stars in the Magellanic Clouds. This in fact turn, by making comparisons its established luminosity to its measured brightness, allows one to evaluate the distance to the star.
Their inferences are based on evidence that they collect during their investigations. Readers learn that scientists gather and interpret evidence and draw conclusions based on this evidence. ... Once scientists have gathered evidence, they use it to make inferences about the things they are investigating.