MODALS|Use of shall and will #!#Use of Would

Read the following statements : S_(1) : An object shall weigh more at pole than at equator when weighed by using a physical balance. S_(2) : It shall weigh the same at pole and equator when weighed by using a physical balance. S_(3) : It shall weigh the same at pole and equator when weighed by using a spring balance. S_(4) : It shall weigh more at the pole than at equator when weighed using a spring balance. Which of the above statements is/are correct ?