Advanced Placement Physics Problem set - Falling bodies For the most part, these problems can be solved using the equations on page one of the EQUATIONS page. The trick is to select the right equation; they are not one-size-fits-all. Each equation has four quantities in it, which means you will need to know three quantities to use any equation. It is recommended that, as you read through a problem, you should write down the given information in a table of data. In doing this you must keep like data together. You should keep a separate table of data if any of these conditions are in place: 1) there is more than one object moving--use a separate table for each; 2) the object in motion has more than one acceleration during the event--use a separate table for each acceleration; 3) an ample description of one part of a trip is given, but questions are asked about another part--use a separate table of data for each part. Have fun. At the end of some of the problems is the word SKETCH. consider this word as an invitation to SKETCH position-, velocity-, and acceleration vs time grarphs for each situation' 1.. A ball is dropped from a tower 100 meters high. A) With what velocity does it hit the ground? B.) How long does it take to make the trip? C.) how far does it travel in half the time calculated in (B)? D.) How fast is it traveling at half the time calculated in (B)? 2. Ball One is dropped from a tower 100 meters high. Ball two thrown downward from the top of tower 1 s .after ball one is dropped. A) What must the initial velocity of ball two if they are to hit the ground simultaneously? B) c) SKETCH 3. Ball one is dropped from a high place at the same moment that ball two is launched from ground level. The balls hit the ground 3 s later. A) how far did ball one fall? B) To what height did ball two rise? C) What was the initial velocity of ball 2? What was the velocity of each ball as they hit the ground? E) SKETCH solution 4 A brick is dropped from the roof off a tall building. A tenant gazing out the window sees the brick traverse the window top to bottom (a distance of 2 m) in .25 s. how far did the brick fall before reaching the window? 5. A hot air balloon is rising at a constant rate of 10 m/s. When the balloon reaches an altitude of 100 m, a sand bag is dropped from the balloon A) How long is the sand bag airborne? B. With what velocity does the sandbag hit the ground? C) SKETCH. solution 6. Now we find an elevator car (with no ceiling) rising at a rate of 4 m/s. As the car reaches a mark 10 m above ground level, a ball is launched from the floor of the car with a velocity of 8 m /s (with respect to the car). A) To what height (relative to ground) does the ball rise? B) Where is the elevator when the ball returns to the car? C) How long is the ball in flight? D) SKETCH 7. Now we find an elevator car (with ceiling innstalled) rising at a rate of 4 m/s. the car is 4 m tall. Suddenly, a bolt becomes detached from the ceiling and falls to the floor. a) How far (with respect to a fixed point on the shaft) does the bolt travel from ceiling to floorB) ow long does this take? c) SKETCH 8. The following question regarding elevator safety is often asked. An elevator car is 10 m above the bottom of the shaft when the cable snaps. All redundant safety mechanisms fail. The only hope for passengers is to jump from the floor at the moment of impact. A) What jumping speed makes this caper survivable? B) Is this scenario plausible? 9. A bowling ball falls from rest from a diving board and hits the water one second later with some velocity. It then sinks to the bottom with this same constant velocity, striking the bottom 4 s after hitting the water surface. a) How deep is the water? b) SKETCH. 10.A ball falls from rest from a height of 4 m and subsequently rebounds to a height of 3 m. The ball is on the floor for .025 sec. a) What acceleration does the ball experience while it is on the floor? b) SKETCH 11. A BASE jumper leaves a high place and falls without friction for 3 s. She then deploys a parachute which opens instantly and gives her an acceleration of 3 m/s/s. She hits then ground with a speed of 5/m/s. A) From what height did she jump? B) For how long was she airborne? C) SKETCH. Return to previous page  This page was last reviewed 01/23/09