Sorry! couldn't edit more info on my last question! re asking the scale on the horizontal axis is 7.5 s per division and on the vertical axis 2.8 m per division. what is the position when t = 22.5 s?

The position isn't changing ! The object is not moving. It's just sitting there. No matter what 't' you're interested in, the position is exactly the same as it has been since t=0 .

That's (4 divisions) x (2.8 m/div). I'm sure you can calculate the number of meters.

found in the nucleus

has mass of one amu

the answer is 12 as i may remember

: )