10.1

10.2

10.3

10.4

10.5

10.6

10.7 d = ½ g t 2 d = 5 m g = 10 m/s 2  t = sqrt (2d/g) t = sqrt (1) t = 1 second Time to hit ground = 1 second In that 1 second, horizontal distance travelled = 20m  Horizontal speed = 20 m/s

10.8

10.9

10.10

10.11

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

) 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 A) 0 g. B) 1 g downward. C) 1 g upward. D) larger than 1 g. E) none of these. 2) A hunter on level ground fires a bullet at an angle of 10 degrees below the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first? A) the dropped one B) Both hit at the same time. C) the fired one

) Which would require the greater change in the Earth's orbital speed (30 km/s); slowing down so the Earth crashes into the sun, or speeding up so the Earth escapes the sun? A)slowing down B)same each way C) speeding up 4) A projectile is thrown into the air at an angle of 50 degrees and lands on a target that is at the same level at which the projectile started. It will also land on the target if it is thrown at an angle of A)40 degrees. B) 45 degrees. C) 55 degrees. D) 60 degrees. E) none of these.

) From Earth, one satellite appears to overtake another. The faster satellite is A)higher. B)lower. C) can't say. 6) A gun with a muzzle velocity of 100 m/s is fired horizontally from a tower. Neglecting air resistance, where will the bullet be 1 second later? A) 50 m down range B) 98 m down range C) 100 m down range D) 490 m down range E) none of these

) A ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation of 5 m above the ground. The player sees the ball land 20 m down range. What is the player's pitching speed? A) about 5 m/s B) about 10 m/s C) about 20 m/s D) about 25 m/s E) none of these 8) An object is thrown vertically into the air. Because of air resistance, the time for its descent will be A)longer than the ascent time. B) equal to the ascent time. C) shorter than the ascent time. D) not enough information given to say.

) What prevents satellites such as the space shuttle from falling? A) the absence of air drag B) gravity C) centrifugal force D) centripetal force E) Nothing; they continually fall all around the earth. 10) A "weightless" astronaut in an orbiting shuttle is A) beyond the pull of gravity. B) shielded from the Earth's gravitational field. C) pulled only by gravitation to the shuttle which cancels the Earth's gravitational pull. D) like the shuttle, pulled by Earth's gravitation. E) none of these.

) Earth satellites are typically more than 100 km high so as to be above the Earth's A)gravitational field. B)atmosphere. C) both of these. 12) A rocket coasts in an elliptical orbit about the Earth. To attain escape velocity using the least amount of fuel in a brief firing time, should it fire off at the apogee, or at the perigee? (Hint: Let "Fd = change in KE" guide your thinking.) A) perigee, where it is closest and fastest B) apogee, where it is farthest and slowest C) same either location

) An airplane flies at 40 m/s at an altitude of 50 meters. The pilot drops a heavy package which falls to the ground. Where, approximately, does the package land relative to the plane's new position? A) beneath the plane B) 400 m behind the plane C) 500 m behind the plane D) more than 500 m behind the plane E) none of these. 14) Acceleration is greater for a satellite when it is at the A)same at both places. B)perigee. C) apogee.

) The radial velocity of an Earth satellite is its velocity A) attributed to satellites moving in any direction. B) parallel to the surface of the Earth. C) perpendicular to the surface of the Earth. D) none of these. 16) A satellite in an elliptical orbit travels at constant A) acceleration. B) velocity. C) speed. D) all of these. E) none of these.

Answers -- MULTIPLE CHOICE. The one alternative that best completes the statement or answers the question.

10.22 Chapter 10 1) Answer: B 2) Answer: C 3) Answer: A 4) Answer: A 5) Answer: B 6) Answer: C 7) Answer: C 8) Answer: A 9) Answer: E 10) Answer: D 11) Answer: B 12) Answer: A 13) Answer: A 14) Answer: B 15) Answer: C 16) Answer: E