In a weightless environment, an astronaut lose about 1.5% calcium in their bodies per month. suppose some astronauts flew to mars. assuming the astronauts did not lose or gain calcium while on mars, they would lose 17% of the calcium tin their bodies due to the round trip flight. estimate the number of months the round trip flight would take.

  12.3 months

Step-by-step explanation:

You want the number of months (m) such that ...

   1 - 17% = (1 -1.5%)^m

Taking logarithms:

  log(0.83) = m·log(0.985)

  m = log(0.83)/log(0.985) ≈ 12.3 . . . . months

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

-7/8

step-by-step explanation:

instead of subtracting you add the -6/8 and -1/8