Program 1.1. 방사성 물질 감쇠

PROGRAM Radioactive_Decay
!---------------------------------------------------------------------------------
! This program calculates the amount of a radioactive substance that
! remains after a specified time, given an initial amount and its
! half-life. Variables used are :
! 		InitialAmount			: initial amount of substance (mg)
!		HalfLife					: Half-life of substance (days)
!		Time						: time at which the amount remaining is calculated (days)
!		AmountRemaining	:  amount of substance remaining (mg)
!
! Input	: InitialAmount, HalfLife, Time
! Output	: AmountRemaining
!---------------------------------------------------------------------------------

IMPLICIT NONE

	REAL :: InitialAmount, HalfLife, Time, AmountRemaining

	! Get values for InitialAmount, HalfLife, and Time.

	PRINT *, "Enter initial amount (mg) of substance, its half-life (days)"
	PRINT *, "and time (days) at which to find amount remaining:"
	READ *, InitialAmount, HalfLife, Time

	! Compute the amount remaining at the specified time.
	AmountRemaining = InitialAmount * 0.5 ** (Time / HalfLife)

	! Display AmountRemaining.
	PRINT *, "Amount remaining =", AmountRemaining, "mg"

	pause
END PROGRAM Radioactive_Decay