A hypodermic needle consists of a syringe of radius 8.30*10^-3 m,
connected to a needle with an inner
radius of 2.45*10^-4 m. A nurse pushes
the plunger at 0.00700 m/s, and the
fluid flows through the needle and into
the air. How fast does the liquid come
out of the needle?

(2) (a) you have a simple circuit that consists of only a battery (δvbat=1.5v) and two resistors with resistance r1=10ω and r2=5ω, connected in series with each other. what is the current running through the battery? (b) you re-arrange your circuit so now r2 is attached in parallel to r1 rather than in series. what is the current running through the battery? (c) you add an additional resistor r3=7ω on the same branch as r2. what is the current running through the battery? (d) what is the power dissipated in r3?