3-6 Projectile Motion A swimmer runs horizontally off a diving board with a speed of 3.32 mls and hits .the water at a horizontal distance of 1.78 m from the end of the board. (a) How high above the water was the diving board? (b) If the swimmer runs off the board with a reduced speed, does it take more. less, or the same time to hit the water? 3-? Projectile Motion The \"hang time\" of a punt is measured to be 4.50 5. if the ball was kicked at an angle 0 630" above the horizontal and was caught at the same level from which it was kicked, what was its initial speed? 3-8 Projectile Motion . Astronomers have discovered several volcanoes on the Jovian moon lo. One of them ejected lava to a maximum height of 2.00 at 105m. if the acceleration due to gravity on Io is 1.30 mfsz, what is the initial speed of the lava? (b) If this volcano were on Earth. would the maximum height of the ejected lava be greater than, less than. or the same as on lo? Explain. 3-9 General Problem A particle leaves the origin with an initial velocity v9 = (2.4 mls) x. and moves with constant acceleration a = (-1.90 mlszj x + (3.20 mlsz) y. (a) How far does the particle move in the x direction before turning around? (b) What is the particle's velocity at this time? - 3-10 General Projectile Problem Find the launch angle for which the range and maximum height of a projectile are the same. 3-11 Addition of Velocities The pilot of an airplane wishes to y due north. but there is a 65 kmi'hr wind blowing toward the east. (3) In what direction should the pilot head her plane it its speed relative to the air is 340 kmlhr? (b) Draw a vector diagram that illustrates your result in part (a). (c) If the pilot decreases the air speed of the plane. but still wants to head due north, should the angle found in part (a) be increased or decreased? Answers fro Problem Sets I (Ch. 1 & 2) and II (Ch. 3) 1-1 1.37 x 108 calcs/us 2-1 d = 15.0 m Ax = 10.0 m 1-2 18.1 ft3 2-2 6.03 m/s 1-3 3.00 x 108 m/s 2-3 (a) Graph (parabola) 1-4 ~ 105 seats (b) -2.00 m/s = Vave (c) 2.00 m/s = Vave 1-5 6.75 x 10-4 mm 2.66 x 10-5 in. 2-4 (a) 2.00 m/$2 (b) 0.00 m/$2 (c) -0.500 m/$2 2-5 t = 5.83 s 2-6 a = 3.84 x 104 m/$2 2-7 (a) t = 5.71 s (b) a = -0.175 m/s (c) v = 2.16 m/s (i.e. more than 2.1 m/s) 2-9 (a) vo = 24.8 m/s (b) t = 0.702 s by quad. Formula 2-8 t = 2.73 s 3-1 A has greater x-comp. 3=6 (a) y = 1.41 m B has greater y-comp. (b) Vertical time depends only on vertical height and g 3-2 (a) A + B= 11.2 at 0 =-26.6 (b) A - B = 11.2 at 0 = 207 3-7 Vo = 24.8 m/s (c) B - A = 11.2 at 0 = 26.6 3-8 (a) Voy = 849 m/s 3-3 Displakm at 0 = 15.3 S of W (b) Ay = 3.67 x 104 m i.e. less, due to greater g on Earth 3-4 Az = 37.3 m Ax = 43.6 m 3-9 (a) Ax = 1.52 m Ay = 30.5 m (b) v = 4.04 m/sy 3-5 (a) x = 9.90 m 3-10 0 = 76.0 (b) y = 0.993 m 3-11 (a) 0 = 11.0 W of N (b) Decr. speed means increased e