The spaceship Lilac, based on the Purple Planet, is 759 m 759 m long, as measured at rest. When Lilac passes Earth, observers there measure its length to be 688 m 688 m . At what fraction of the speed of light is Lilac moving with respect to Earth?

The speed of Lilac is 0.422 times of the speed of light.

Explanation:

Given that,

Length of the spaceship Lilac at rest,

When Lilac passes Earth, observers there measure its length to be 688 m, L = 688 m

We need to find the speed of light is Lilac moving with respect to Earth. The formula of length contraction is given by :

So, the speed of Lilac is 0.422 times of the speed of light.

ill do it for 100, also this isnt 80 its 40

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more