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1 1989 J. Wçston Walch, Publishcr Physics Compu-Sheeff 1 \. v t H = - voo k v1-v--t 1. A ball rolls with a speed of 2 rn/s across a table top that is 1 meter above the floor. Upon reaching the Projectile Motion Name 22S 6 c / PROJECTLE MOTON Date: 10 \ 4% velocityof5.00 ms. The floorofthe crater is 100 meters below the astronaut What horizontal distance gravity on the moon is only 1/6 of that on eatth.).. 5. An astronautstands on the edge ofa lunar crater and throws a half-eaten Moon Pie horizontally with a will the Moon Pie travel before hitting the floor ofthe crater? (Remember that the acceleration due to. bofthramp.howhighistheeadoftheranipabovethelandingarea? 4. Askierleavesthehorizoatalendofthe ranipwwa velocityof25 m/sandlandsl0 metezsfromthe \ : - 4% -j.%% N S c( r (2 1 4 eftthcbarrel? 9 meters from the ground. Disregarding air friction, at what speed must the bullet have been traveling as it 3. A rifle is fired horizontally. The bullet is found to have traveled 200 meters. The rifle barrel is O2Ov shouldshecelease the package? iij:...2 L velocity of 100 rn/s. fair friction is disregarded, how far in advance ofthestarving explorets drop zone 2. A rescue pilot drops a survival kit while her plane is flying atan altitude of2000 meters with a forward = v{ Jo i O9rr \ 2mjc t spotfromthetable? edge ofthe table, it follows a parabolic path to its landing spot on the floorilow far along the floor is this H.j

2 PROJECTLE MOTON PRACTCE. 1]1 ii 11! 7 1. Stefan kicks a soccer ball off a cliff with ahorizonlx,eed of 15 m/s. f it lands 28 meters from the base of the cliff, how high is the cliff? h -irr.1 2. Natalie accidentally shoves a small rock off a cliff that is 45 meters high. f it lands 62 meters from the base of the cliff; what was the original horizonta viocity with which t left the cliff? _4 - r. 4 / 3. John kicks a football (exactly horizontally) off the bleachers. t reaches the ground in 1.7 seconds. How high are the bleachers? 4. Alex is waiting for a package to be dropped from an airplane. She calculates where to stand (300 meters ahead of the drop location.) f t4e package lands in 5.4 seconds (ignore air resistance!), what was, the horizontal speed of the airplane? 5 Mike is running to catch a ball that was thrown from the top of a hill (from a height of 16 meters). f the bail was thrown with a horizontal speed of 11 m/s, how far from the footofthe hill should Mike stop iiiiining and catciiiff. Vt r( /7 ic (, i,(

3 6. a stick of gum to her friend when she is on a cheerleader s shoulder. end catches it in 0.2 seconds, how high was Erica? Assume she threw the 1 açiziita velociy.qy. 7. Scott throws a baseball. with a horizontal velocity of 7.8mJs. f he throws it off a tower that is 23 meters high, how far from the base of the tower will it land? 8. While in Minnesota, Mei Mei throws a snowball (horizontally, of course) from the top of a snow fort that is 4.5 meters high. f it bits her friend (who is 10 meters away) iconds, with what speed did she throw the ball? 9. While working at the country club, Ted almost gets hit by a golf ball that was hit from the top of a knoll (height = 3.1 meters). He was 57 meters away, so he can use his awesome knowledge of physics to calculate that the horizontally projected golf ball had a speed of Arya is on the Golden Gate Bridge when he notices a tourist throw a film canister horizontally off the bridge with a speed of 14 rn/s. At that points the bridge is 63 barge with its midpoint 85 meters from the base of the bridge, will the canister land on the barge or fall in the water? (Assume the barge is 20 meters long.)

4 a, Horizontally Launched Projectile Motion Quiz(E) Name Period Date Equations: x = vx t y 5 t 10 t 1. When an object is in projectile motion, it is accelerating a. in both the horizontal and vertical directions b. in the horizontal direction only (Elivrtical direction only JEiWneither direction ) 2When analyzing projectile motion, the vertical motion can projectile were ft e 4L and the horizontal motion can be analyzed as 3. f air resistance is included in analysis of projectile motion, the maximum vertical height is than if it were not included. 4. f air resistance is included in analysis of projectile motion, the horizontal range is, than if it were not included. 5. A helicopter, with a horizontal velocity of 74 ms, drops a package that reaches the ground in 4.6 seconds. a. How far has the package traveled horizontally? b. How far did it fall vertically? ) c. What was its vertical velocity just before it hit the ground? Mrs. Celin is preparing to fire her potato cannon horizontally off the edge of the roof of HSN, 15 m high. She thinks the potato will exit the cannon at 37 m/s. a. What is her prediction for how far away the potato will land? x b. What is her prediction for how long it is in the air? ij

5 7. After confidently predicting the horizontal distance and the time in the air, Mrs Celin fires the cannon. Students, with stopwatches and metersticks in hand, stand below to time the flight and measure the horizontal distance. The average measured horizontal distance is determined to be 25 m. Time data was unreliable and none can be used in further calculations. a. Use the time you calculated in #6 and the measured horizontal distance of 25 m to recalculate the horizontal velocity of the potato as it left the cannon. b. Can you explain why the predictions don t match the measurements? 8. You are a U of Colorado physics major and notice that the projectile motion simulation does not include a choice of W for different planets. You are recruited to write an additional program that gives the user a choice of planets. Remember on earth the acceleration due to gravity is 10 rn/s 2. a. How would you modify the equations that the program uses (and you use in class) For the moon where the gravity is 1/6 of earth s? For Jupiter where the gravity is 2.4 times greater than earth s? b. Recalculate # Sb as if you were on Jupiter.

6 J. A football is kicked at an angle up into the air. f air resistance is ignored, describe the acceleration of the football: a. iti zero at (t is -10 ms at all times (negative is downward) c. it is zero at the top of the trajectory at all times d. it is positive on the way up and negative on the way down A. A ball is thrown straight off a cliff with a horizontal velocity of 15 rn/s. THS S REAL LFE and you must include air resistance. Right before the ball hits the ground, the horizontal velocity is a. 15 rn/sec b. zero c. greater than 15 rn/s (ss than 15 rn/s..4 gnoring air resistancthhorizontal component of the projectile s velocity a. is constant b. accelerates Which of the following is NOT an example of projectile motion? a. a volleyball served over a net b. a baseball hit by a bat acannonball shot off a cliff 7 d. an airplane flying flat and level Each of the diagrams below shows a projectile with different horizontal velocity or different starting height. LABEL which projectile(s) hit the ground FRST. LABEL which projectile(s) hit the ground LAST. Some may hit at the same time. a r

7 frc3 For numbers Z use the following situation. A cannonball is launched horizontally from a tower of a castle with a speed of 12 rn/s and at a height of 16 meters, gnore air resistance. Use a -10 m/s 2. \ What is the vertical velocity at the exact time of the launch? b. -12 rn/s c. -10 rn/s d.-2m/s a. 0 rn/s b. -12 rn/s () d. -30 rn/s,,i1. f the cannonball is launched from a higher spot on the castle, the fmal vertical velocity of the cannonball would be: a. the same (heater) c. less. )4.. f a bigger cannon with greater speed were used, the horizontal distance traveled would be: a. the same (i. greater c. less. n her physics lab experiment, Wanda rolls a marble down a ramp and off the table. The marble has a horizontal velocity of 2.1 rn/s as it rolls off and it lands 60 cm from the edge of the table, How high is the table? 4 (: