An airplane flies in a horizontal circle of radius 500 m at a speed of 150 m/s. If the plane were to fly in the same 500 m circle at a speed of 300 m/s, by what factor would its centripetal acceleration change?
a. 0.25
b. 0.50
c. 1.00
d. 2.00
e. 4.00
[Ques. 2] Two pistons push down on the fluid filling two cylinders connected by a narrow hose, as shown in the figure. The area A1 is 1 square inch, and the area A2 is 10 square inches. A force of 4 pounds is exerted downward on piston 1, as shown.
The force
F2 needed to keep piston 2 in place is 40 pounds.
a.
True
b.
False
[Ques. 3] A skydiver of 75 kg mass has a terminal velocity of 60 m/s. At what speed is the resistive force on the skydiver half that when at terminal speed?
a. 15 m/s
b. 49 m/s
c. 30 m/s
d. 42 m/s
e. 36 m/s
[Ques. 4] A boy on board a cruise ship drops a 30.0 gm marble into the ocean. If the resistive force proportionality constant is 0.500 kg/s, what is the terminal speed of the marble in m/s?
a. 0.147
b. 0.294
c. 0.588
d. 1.18
e. 2.35
[Ques. 5] Two pistons push down on the fluid filling two cylinders connected by a narrow hose, as shown in the figure. The area A1 is 1 square inch, and the area A2 is 10 square inches. A force of 4 pounds is exerted downward on piston 1, as shown.
The pressure on
A2 is 40 psi.
a.
True
b.
False
[Ques. 6] Frank says that if you release the string when swinging a ball in a horizontal circle, the ball flies out in the radial direction defined by the string at the instant you release the ball. John says that it flies out along a tangent line perpendicular to the string, and that it then drops straight down to the ground. Which one, if either, is correct?
a. Frank, because the centrifugal force is no longer counteracted by the string.
b. Frank, because balls naturally fly straight out.
c. John, because there is no centrifugal force.
d. John, because balls fall straight down when released.
e. Neither, because although there is no centrifugal force, and the ball's velocity is tangent to the circle at the instant of release, the ball then follows a parabolic trajectory.
[Ques. 7] Two pistons push down on the fluid filling two cylinders connected by a narrow hose, as shown in the figure. The area A1 is 1 square inch, and the area A2 is 10 square inches. A force of 4 pounds is exerted downward on piston 1, as shown.
The pressure on
A1 is 4 psi.
a.
True
b.
False
[Ques. 8] A hornet circles around a pop can at increasing speed while flying in a path with a 12-cm diameter. We can conclude that the hornet's wings must push on the air with force components that are
a. straight down.
b. down and inwards.
c. down and outwards.
d. down and backwards.
e. down, backwards and outwards.
[Ques. 9] A hornet circles around a pop can at constant speed once per second in a path with a 12-cm diameter. We can conclude that the hornet's wings must push on the air with force components that are
a. straight down.
b. down and inwards.
c. down and outwards.
d. down and backwards.
e. down, inwards and backwards.
[Ques. 10] The figure shows a distance vs. time graph of an object with three distinct regions, I, II, and III.
The objects acceleration is zero in region(s)
a.
I.
b.
II.
c.
III.
d.
no regions
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