Suppose we could shrink the earth without changing its mass. at what fraction of its current radius would the free-fall acceleration at the surface be three times its present value?

Explanation:

The acceleration due to gravity on the surface of the Earth is given by:

where

G is the gravitational constant

M is the mass of the Earth

R is the radius of the Earth

Here we want to find the new Earth radius R' for which the gravitational acceleration at the surface, g', would be 3 times the current value of g:

So we would have

Solving the equation for R', we find

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer

statement #3 on andre"s list is false.