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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) An airplane travels at 141 km/h toward the northeast. What is its component of velocity due north? 1) _______
A) 141 km/h B) 100 km/h C) 41 km/h D) 110 km/h

Figure 10-B

2) A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, its verticalcomponent of velocity 2) _______
A) remains unchanged.
B) decreases.
C) increases.

3) A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, its horizontal component of velocity 3) _______
A) increases.
B) decreases.
C) remains unchanged.

4) A stone is thrown horizontally from the top of a cliff. One second after it has left your hand its verticaldistance below the top of the cliff is 4) _______
A) 15 m. B) 10 m. C) 5 m.

5) Throw an object upward at a 45 degree angle. With no gravity it will follow a straight-line path. But because of gravity, at the end of 1 second, it is 5) _______
A) about 15 m below the straight line.
B) about 5 m below the straight line.
C) about 10 m below the straight line.

6) Roll a bowlingball off the edge of a table. As it falls, its horizontal component of velocity 6) _______
A) increases. B) remains constant. C) decreases.

7) A bullet fired horizontally from a rifle begins to fall 7) _______
A) after air friction reduces its speed.
B) as soon as it leaves the barrel.
C) neither of these

8) A projectile is launched vertically upward at 50 m/s. If airresistance is negligible, its speed upon returning to its starting point is 8) _______
A) 50 m/s. B) less than 50 m/s. C) more than 50 m/s.

9) An Earth satellite is simply a projectile 9) _______
A) approaching the earth from outer space.
B) floating motionless in space near the earth.
C) freely falling around the earth.

10) Earth satellites are typically more than 100 km highso as to be above the Earth's 10) ______
A) gravitational field. B) atmosphere. C) both of these

11) A projectile is fired horizontally in a region of no air resistance. The projectile maintains its horizontal component of velocity because 11) ______
A) it is not acted on by any horizontal forces.
B) it is not acted on by any forces.
C) the net force acting on it is zero.
D) ithas no vertical component of velocity to begin with.
E) none of these

12) A hunter on level ground fires a bullet at an angle of 10 degrees above the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first? 12) ______
A) the dropped one
B) the fired one
C) Both hit at the same time.

13) A hunter on levelground fires a bullet at an angle of 2 degrees below the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first? 13) ______
A) the fired one
B) the dropped one
C) Both hit at the same time.

14) A bullet fired horizontally over level ground hits the ground in 0.5 second. If it had been fired with twice the speed in thesame direction, it would have hit the ground in 14) ______
A) more than 0.5 s. B) 0.5 s. C) less than 0.5 s.

15) An object is dropped and freely falls to the ground with an acceleration of 1 g. If it is thrown upward at an angle instead, its acceleration will be 15) ______
A) 0 g.
B) 1 g upward.
C) 1 g downward.
D) larger than 1 g.
E) none of these

16) A projectile islaunched at ground level an angle of 15 degrees above the horizontal and lands down range. What other projection angle for the same speed would produce the same down-range distance? 16) ______
A) 50 degrees
B) 30 degrees
C) 75 degrees
D) 90 degrees
E) 45 degrees

17) A projectile is fired into the air at an angle of 50 degrees with the ground and lands on a target that is at the same...