Answer:
Number of days needed = 57
Explanation:
Depth of well = 115 feet
Distance traveled in day = 3 feet up
Distance traveled in night = 1 feet down.
Total displacement in 1 day = 3 - 1 = 2 feet up
When the snail reaches 112 feet up, the next 3 feet up motion on day will make it reach the top.
After 56 days the displacement of snail is 112 feet.
On the next day it moves up by 3 feet and reaches out of well.
Number of days needed = 57
Answer:
speed of star is 1.37 × m/s
it is approaching to earth because wavelength of star is decreasing than rest
if emit same wavelength it does not move anywhere
it will remain steady condition with respect earth
Explanation:
given data
wavelength = 656.5 nm
rest wavelength = 656.8 nm
to find out
the speed of the star , is it approaching
solution
we know here equation that is
wavelength shift / wavelength at rest = velocity of source / speed of light
so put all value and find
velocity of source = 3 × × 3 ×
/ 656.8 ×
velocity of source star = 1.37 × m/s
and
it is approaching to earth because wavelength of star is decreasing than rest
and
if emit same wavelength it does not move anywhere
it will remain steady condition with respect earth