Directions

1. ans: 29 cm/s; rate =area*velocity.

2. ans: 13 m/s; since P remains constant, initial 0.5r*v² must = final 0.5r*v² + r*g*h. Notice that r cancels out.

3. ans: 27.6 m/s; the support pressure needed is r*g*h of the water in the straw, 1000*9.8*0.05 Pa. This pressure is compensated by 0.5*r*v² of the air, 0.5*1.3*v².

4. ans: 1.9 m/s; also a r*g*h = r*v²/2 problem, but here the r's are the same and cancel.

5. ans: 2 x10⁵ Pa, 15 m/s; a P + r*v²/2 = constant problem, together with r*A =constant (so final v = 3x initial v).

6. ans: 9.8 ATM; yet another P below = r*g*h above problem.

7. ans: 27 m/s; a r*v*A = constant problem.