Question

pls pls help ...
tomorrow is my exam...​

Answer 1

Answer:

W1 = G M m / R1^2        weight of mass m at surface

W2 = G M m / R2^2       weight of mass at distance R2 from center of earth

W2 / W1 = (R1 / R2)^2

W2 / W1 = (R1 / (R1 + h))^2

W2 / W1 = 1 / (1 + h / R1)^2 = 1 / (1 + 2 h / R1 + (h / R1)^2)

W2 / W1 = 1 / (1 + 2 h / R1)     since the term (h / R1)^2 is very small

W2 / W1 = 1 - 2 h / R1     if you use the binomial expansion

(You can start out using W1 / W2 and get the same fractional change without using the binomial expansion since the two methods differ only by the square term that was omitted)

I couldn't be sure of the value of h from the posted question, but if you multiply the fractional change by 100 then you obtain the percentage change.