You have to be kidding.
If you are having difficulty with this, then Physics will be very anguishing for you. What you are asking is normally a seventh grade mapping skill.
Use proportions:
1cm/10= 2cm/x
If a vector that is 1 cm long represents a velocity of 10 km/h, what velocity does a vectory 2 cm long drawn to the same scale represent?
3 answers
10 km/h x 2 cm/1 cm=??
I am in 8th grade. I'm taking advanced classes.