Answer:
Explanation:
Change in length of spring = 2.13 m
Component of weight acting on spring = mg sinθ
so
mg sinθ = k x where k is spring constant and x is total stretch due to force on the spring.
Here x = 2.13
mg sin17 = k x 2.13
31 x 9.8 sin17 = k x 2.13
k = 41.7 N/m
b ) In case surface had friction , spring would have stretched by less distance .
It is so because , the work done by gravity in stretching down is stored as potential energy in spring . In case of dissipative force like friction , it also takes up some energy in the form of heat etc so spring stretches less.
Answer:you riding your bike at 12m/s
Explanation: this is because momentum P = mass x velocity. With a bigger mass and a velocity of about 12m/s, you really have a great momentum.
Answer:
Explanation:
Scientific evidence takes note of the pattern of evolution. The evidence exists in a variety of categories, including direct observation of evolutionary change, the fossil record, homology, and biogeography.
Examples of the categories with their respective examples are:
Direct observation of evolutionary change: Development of drug resistant bacteria
Fossil record: Discovery of transitional forms of horses, Discovery of shells of extinct species
Homology: Similarities in mammalian forelimbs, Same genetic code in fireflies and tobacco plants, Vestigial pelvis in right whales
Biogeography: Similarity of endemic island species to nearby mainland species, The high concentration of marsupial species in Australia
It all comes to the doppler effect, the red shift means that the galaxy is moving away from us. The redshift is a result from the doppler effect, so as the galaxy moves away the wavelength expands, increasing the wavelength which responds to the red light.
