On earth you have a mass of 140kg in space you will have a mass of how many kg

If your mass is 140kg , then your mass is 140kg.  

It doesn't make a bit of difference what time it is, whether you're happy or sad, sleeping or lifting weights or running, whether it's raining or shining, hot or cold, climbing a mountain or falling out of an airplane, on the surface of a planet, asteroid, comet or star, or floating or falling through empty lonely outer space.  Your mass is your mass.  The only way it can change is if YOU make changes in yourSELF, like eating a big steak, sweating through a long tough workout, or skipping dinner, or growing to maturity.

(I guess you're already pretty mature.  If your mass is 140kg, then you weigh about 308 pounds when you're on Earth.)

  distance on the y-axis and time on the x-axis.

explanation:

the instantaneous velocity = change in position/time taken

the slope of the graph should give instantaneous velocity.

  slope of a graph = change in value of y -axis / change in values of x -axis

  comparing both the equations

    change in value of y -axis = change in position

  change in values of x -axis = time taken

so position values should be on the y axis and time values should be on the x axis.

distance on the y-axis and time on the x-axis.