Step-by-step explanation:
Sure, here's the completed VPython code to move the ball up seven units:
from vpython import *
# create a sphere object with position (0,0,0)
ball = sphere(pos=vector(0,0,0), radius=0.5, color=color.blue)
# move the ball up seven units
ball.pos.y += 7
The ball.pos attribute is a vector object with three components (x, y, z) representing the position of the ball in 3D space. To move the ball up seven units, we simply add 7 to the y-component of the position vector using the += operator.