9. The acceleration due to gravity on the Moon is 1.62 m/s2, approximately a sixth of the value on Earth. For a given initial velocity v0 and a given launch angle θa, the ratio of the range of an ideal projectile on the Moon to the range of the same projectile on Earth, RMoon / REarth, will be approximately
a) 6.
b) 3.
c) 12.
d) 5.
e) 1.
10. A baseball is launched from the bat at an angle θ0 = 30.0° with respect to the positive x-axis and with an initial speed of 40.0 m/s, and it is caught at the same height from which it was hit. Assuming ideal projectile motion (positive y-axis upward), the velocity of the ball when it is caught is
a) (20.00 x + 34.64 y) m/s.
b) (-20.00 x + 34.64 y) m/s.
c) (34.64 x- 20.00 y) m/s.
d) (34.64 x + 20.00 y) m/s.
11. In ideal projectile motion, the velocity and acceleration of the projectile at its maximum height are, respectively,
a) Horizontal, vertical downward.
b) Horizontal, zero.
c) Zero, zero.
d) Zero, vertical downward.
e) Zero, horizontal.
12. In ideal projectile motion, when the positive y-axis is chosen to be vertically upward, the y-component of the acceleration of the object during the ascending part of the motion and the y-component of the acceleration during the descending part of the motion are, respectively,
a) Positive, negative.
b) Negative, positive.
c) Positive, positive.
d) Negative, negative.
13. In ideal projectile motion, when the positive y-axis is chosen to be vertically upward, the y-component of the velocity of the object during the ascending part of the motion and the y-component of the velocity during the descending part of the motion are, respectively,
a) Positive, negative.
b) Negative, positive.
c) positive, positive.
d) Negative, negative.
14. A projectile is launched from a height y0 = 0. For a given launch angle, if the launch speed is doubled, what will happen to the range R and the maximum height H of the projectile?
a) R and H will both double.
b) R and H will both quadruple.
c) R will double, and H will stay the same.
d) R will quadruple, and H will double.
e) R will double, and H will quadruple.
15. A projectile is launched twice from a height y0 = 0 at a given launch speed, v0. The first launch angle is 30.0°; the second angle is 60.0°. What can you say about the range R of the projectile in these two cases?
a) R is the same for both cases.
b) R is larger for a launch angle of 30.0°.
c) R is larger for a launch angle of 60.0°.
d) None of the preceding statements is true.