George is planning an experiment to see how fast different sized cans of soup can roll down a ramp in his kitchen. He will be rolling them down a ramp and them time how fast it take them to travel 1 meter after the ramp. As George's Lab partner, what would be an appropiate hypothesis for George's Experiment? a
The heavier cans will be faster, because science
b
If the can is denser, then it will take less time to cross 1 m, because gravity made it go faster down the ramp
c
The denser the soup can gets, the faster it will go, because gravity.
d
If the can is heavier, it will roll faster down the ramp due to gravity.

When someone eats food

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero. 

Electrons have a negative charge if that's what you're asking