Jill can throw a ball at a speed of 80 mph, consistently, on the ground. She gets into the back of a truck, which drives down the road in the $+x\text{-direction}$ direction at 30 mph. Jill faces the back of the truck and throws a ball. According to Galilean relativity, what is the $x\text{-component}$ component of the velocity of the ball relative to the ground?

• A. $-110\mathrm{ mph}$
• B. $30\mathrm{ mph}$
• C. $50\mathrm{ mph}$
• D. $80\mathrm{ mph}$
• E. $110\mathrm{ mph}$
• F. $-50\mathrm{ mph}$