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Section 21.12 Applying Forces and Fields
Activity 21.12.1 . Charge Launcher I.
You decide to make a launcher by gluing a
\(+20 \mathrm{~mC}\) point charge at the bottom of a vertical tube that is
\(10 \mathrm{~m}\) long.
(a) Make a qualitatively accurate vector map of the electric field in the tube.
(b) Find the magnitude of the electric field in
\(\mathrm{N/C}\) halfway to the top of the tube.
(c) Find the magnitude of the electric field in
\(\mathrm{N/C}\) at the top of the tube.
Activity 21.12.2 . Charge Launcher II.
Your projectile for the charge launcher above is a heavy metal ball with mass
\(900 \mathrm{~kg}\) and charge
\(+5 \mathrm{~mC}\text{.}\) The projectile begins halfway up the tube.
(a) Find the net force and acceleration on the projectile at its starting point.
(b) As the projectile moves, is the acceleration constant? At what point, if any, is the acceleration zero? What does this mean for the projectile?
