HW#11 Ch 4: Motion in Two and Three Dimensions
Instructions: Write the general equation before showing your work to earn full credit.
1. The barrel of a howitzer is elevated at an angle of 45°. The gun fires a 43 kg shell with an initial speed of 564 m/s. a) What height does the shell reach? b) How long is the shell in the air? c) What is the horizontal range of the gun? (Neglect air resistance, even though air resistance will have a large effect.)
2. A pebble thrown horizontally from the top of a 21-m apartment building hits the ground at a point 12 m from the base of the building. a) Find the speed at which the pebble was thrown. b) Find the speed of the pebble just before it hits the ground.
3. A ball bearing is fired into the air from the top of a 71-m cliff. Its initial velocity is 23 m/s at 60° above the horizontal. How far from the base of the cliff does the ball bearing land?
4. A projectile is launched horizontally from the top of the Snyder building, which has a height H. It lands at a horizontal distance H from the base of the building. At what angle (relative to the horizontal) does the projectile strike the ground?