# What is Projectiles: Definition and 193 Discussions

A projectile is any object thrown by the exertion of a force. It can also be defined as an object launched into the space and allowed to move free under the influence of gravity and air resistance. Although any object in motion through space (for example a thrown baseball, kicked football, fired bullet, thrown arrow, stone released from catapult) may be called projectiles, they are commonly found in warfare and sports. Mathematical equations of motion are used to analyze projectile trajectories.

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1. ### MHB Projectiles Problem: Time to Hit Ground from 45m

a ball is projected vitically from the top of a building with hight of 45 m from Erath`s surface . it velocity is determind by the relation v= 40-10t how much time the ball will take to hit the ground?
2. ### Why do heavier projectiles tend to have higher momentum?

I am wondering why heavier bullets have a higher momentum than lighter bullets when using similar powder charges? At the muzzle, a typical 150 grain bullet fired from a 30-'06 will travel at around 3000 ft/s. A 200 grain bullet from the same rifle will travel around 2600 ft/s. (The velocities...

4. ### Deciphering this problem statement: Air resistance on projectiles

I am struggling with our equation and where to plug in my velocities and forces? After looking at my book I don't understand why p(t) would be where I plug in force, and why variable "t" is where we plug our velocity in? When the problem says "what happens if you try to use a polynomial of...
5. ### Armor vs. Fast Projectiles or Slower Weapons

Yeah this is for an RPG. So my understanding is that a bullet would penetrate plate armor (only a few mm thick) while a sword swing even with more KE would not even though both the bullet and the sword have their energy focused into a small area. I assume this has to do with the armor having...
6. ### Find the initial velocity of a water rocket (mass changes)

Homework Statement Find the initial velocity of the boost phase (when water is coming out). Here is everything I know - Mass of rocket with no water is 0.13kg, mass of rocket with water is 1.1kg. The total length of the rocket is 0.48m. The time to the maximum point is 3.46 seconds, and total...
7. ### Plasma Projectiles Versus Metal Armor

So, I'm considering the match up between Goku and, let's say, an armored mech. I wrote out rules for a GURPS game based on Dragon Ball flavor and powers but kind of a more logically consistent version of that universe that I have written probably a couple dozen pages about so far. So, the...
8. ### Find the rate that the distance between two projectiles is changing

Homework Statement The parameteric equations for the paths of two projectiles are given below. At what rate is the distance between the two objects changing at t = pi/2? Homework Equations x1=12cos(2t) y1 = 6sin(2t) x2=6cos(t) y2 = 7sin(t) The Attempt at a Solution I am completely...
9. ### Problem of projectiles

Homework Statement Homework Equations $$h=ut+1/2at^2$$ $$h=x\tan\theta-1/2g\frac{x^2}{u^2\cos^2\theta}$$ The Attempt at a Solution I tried to take a random angle theta for the lower particee and then using the equation of the upper particle tried to solve them together and find condition for...
10. ### Rank velocities of projectiles at landing?

Homework Statement I will attatch the picture. Can someone please help me UNDERSTAND how to rank the velocity vectors at the landing zone?? I am having a really hard time with physics >=[ i don't know how to just look at this graph and rank the velocities. Homework Equations The Attempt at a...
11. ### Question about vacuum powered projectiles

I'm writing a novel and wanted to research a possible weapon I came up with to make sure the physics are at least possible. However, I could not find anything on vacuum-based projectiles other than ping-pong balls, while this is interesting, but it doesn't answer my question on what would happen...
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### Horizontally projected diver

Homework Statement A daring 510N swimmer dives off a cliff with a horizontal leap. What must his minimum speed be just as he leaves the top of the cliff so that he will miss the ledge at the bottom, which is 1.75m wide and 9.00m below the top of the cliff? Homework Equations s=1/2gt^2 ; v=s/t...
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### 2 Projectiles are fired simultaneously

Homework Statement 2 projectiles are fired simultaneously from ground level with same initial speed (u).Both cover same horizontal distance of 160m on reaching the ground level .One of them reaches 6 sec prior to the other.Only gravitational acceleration g=10m/s squared governs the motion of...
14. ### Projectiles launched at complementary angles

Homework Statement a) Show that for a given velocity V_0 a projectile can reach the same range R from two different angles \theta = 45 + \delta and \theta = 45 - \delta, as long as R doesn't go over the maximum range R_{max} = \frac{V_0^2}{g}. Calculate \delta in function of V_0 and R. b)...
15. ### Can magnets on a cylindrical object be used for projectiles?

What I mean is if I have 2 cylinder objects made out of a light wood for example with 6 or so magnets on either face spread evenly and another magnet behind it causing it to spin could it generate a good amount of torque to shoot a small projectile between the two cylinders. To give you a better...
16. ### Finding Projectiles' Flight Times....

Homework Statement Two projectiles are launched from the ground with initial speeds of 100 meters per second. One is launched straight up, the other at a 30-degree angle. How much time elapses between each's return to ground level? Theta = 30 g = 10 m/s Vinitial = 100 Homework Equations y =...
17. ### Vector Nature pf Projectile Motion

Homework Statement If an object had been projected horizontally with the same magnitude as in the depicted situation, how would the motion compare with that of the object in the diagram? (I have drawn the diagram in my attachment and have done questions c and d but I don't understand question...
18. ### Fictional physics problem -- Firing projectiles into Earth orbit

Hi guys, I've recently been reading a lot of Jules Verne and I had a few curiosities that you guys could help with. First, if we were to shoot or fling a bullet to low Earth orbit, what would the muzzle velocity have to be?? Second, instead of a bullet, if we used a capsule with one passenger...
19. ### Ranges of Projectiles With and Without Drag

I recently completed a lab using an online projectile simulator about the range of projectiles. I launched a projectile with different initial speeds (5 m/s, 10 m/s, 15 m/s, 20 m/s, and 25 m/s). For each trial, I did the launch with and without air resistance and I plotted Range (with Air...
20. ### Projectiles in space: Calculating initial velocity

This question is on space and projectiles. It is about comet 67P/ Churyumov-Gerasimenko and the Rosetta/ Philae lander. Question: 67P has a gravitational field strength of 5.2x10^5 N/Kg. After Philae bounced it took 1 hour 50 minutes to reland. Calculate the initial velocity of Philae. Does this...
21. ### Finding Velocity from only distance

Mod note: Moved from technical section, so no template Question: The ace Edward bow can shoot 182.8 meters at a 45 degree angle, it can shoot 12 arrow per minute. What is the performance of the Bow? Attempt: Basically considering the Dx=182.8 meters I assume the Dy is the same considering its...
22. ### Determining the height of an angled projectile after 10m

Homework Statement Jason is practicing his tennis stroke by hitting balls against a wall. The ball leaves his racquet at a height of 43 cm above the ground at an angle of 80° with respect to the vertical. The speed of the ball as it leaves the racquet is 25 m/s and it must travel a distance of...
23. ### Solving Projectiles Problem: Ball Rolls Horizontally Off Stairway

Homework Statement A ball rolls horizontally off the top of a stairway with a speed of 1.52 m/s. The steps are 20.3 cm high and 20.3 cm wide. Which step does the ball hit first? Homework Equations The Attempt at a Solution The book says it's the third step. I tried, using equations...
24. ### MCQ Question related to trajectory of two projectiles

Homework Statement : The trajectort of two projectiles are shown in the figure. Let T1 & T2 be the rime periods and U1 and U2 be their speeds of projection. Then(state the answer with REASON): A) T2 > T1 B) T1 = T2 C) U1 > U2 D) U1 < U2 [/B] (MAYBE, MORE THAN ONE CORRECT) Homework Equations...
25. ### Will the ball clear the net? - Projectiles question

There is a question i have done in my textbook and it initially asks you to calculate: the maximum height of the ball, and how long it takes to arrive at that maximum height. They give you a vertical velocity component of 5m/s. So i made an equation using t= (v-u)/a Which gives me...
26. ### Projectiles and Newtons law help?

The first question is about Newton's Third Law: A boat is moving north at a velocity v=15 km/h a man on the boat throws a ball horizontally with a velocity u=15 km/h how is the motion of the ball w.r.t the man? For this, I thought that because the boat is moving with the same speed as the...
27. ### I with air resistance

Homework Statement I'm currently in computer programming class, and I've finished a project and want to improve on it. We had to figure out how to calculate the gravitational acceleration and time traveled of a projectile to hit a target. I'd like to add horizontal variables in my code, like...
28. ### Measuring rotational speed

I'm planning on carrying out an investigation with a golf ball and projectiles. Is there any type of equipment/sensor that I can used to measure the rotational speed/angular velocity? I know a gun chronograph can be used to detect the velocity but what can I used to detect the angular velocity...
29. ### Horizontal Projectiles. Degree or Radian mode in calculator?

Homework Statement It's a worksheet with questions like : A pelican flying along a horizontal path drops a fish from a height of 5.4 m. The fish travels 8.0 m horizontally before it hits the water below. What is the pelican's initial speed? Homework Equations The Attempt at a Solution [/B]...
30. ### Projectiles problem, help needed

Here is the problem (Q3 (A)); Here's what I have so far; Any help would be appreciated, thank you!
31. ### Projectiles in Air: Is Under Spin Enough to Rise?

Is it theoretically possible to get a round bullet to rise if shot horizontally provided the bullet ( projectile) is given "under spin"?
32. ### Projectiles, and acceleration problems

I'm in a introductory physics course and I don't understand how to solve these problems.
33. ### Maximizing Projectile Efficiency: Energy Conservation in High School Physics

I post here very infrequently, but I'm a high school physics teacher occasionally encountering excellent student questions. Here is one I received today: Since we've been using energy conservation to simplify problems that were annoying earlier in the year (kinematics, mechanics, etc.), can we...
34. ### Question about Projectiles being launched horizontally

Homework Statement Stone is thrown at +15 m/s from top of cliff at 44 meters high. Im looking for the time it takes to reach the bottom and the final answer is 3 seconds. But I don't know how to get there. Equation starts with t^2 =2Y/g Y is initial height meaning -44 meters. The g is...
35. ### Simple question on 2d projectiles

Homework Statement A catapult projects a stone in the normal direction to a playground which slopes at a angle of 10 degrees to the horizontal. The initial speed of the stone is 18 m/s. calculate the range parallel to the playground. Homework Equations the usual ones! The Attempt at a...
36. ### Deriving Velocity For Projectiles

I have a projectile that can only launch at 30 degrees and a target exactly 100m away at the same elevation on flat ground with 1g (9.8m/s2 meters per second per second?) What velocity without (then with) air resistance would the "muzzle velocity" need to be? (with a droplet shape for...
37. ### How do you do projectile calculations, but with drag force?

And how do you find the drag force?
38. ### Best angle to shoot a projectile

Homework Statement A projectile is fired with speed v_0 (velocity subscript zero) at an angle θ from the horizontal as shown in the figure Consider your advice to an artillery officer who has the following problem. From his current position, he must shoot over a hill of height H at a target...
39. ### Projectiles launched at an angle question

Homework Statement An object is thrown from the ground into the air with a velocity of 20.0m/s at an angle of 27.0° to the horizontal what is the maximum height? v= 20.0 m/s a=-9.81m/s^2 angle = 27.0 Homework Equations a=v/t , v= d/t The Attempt at a Solution sin(27.0°) = y/20.0m/s...
40. ### MHB Challenging Applied maths question projectiles

An aircraft flies at a constant height H and constant velocity V. When the aircraft has flown directly over a gun on the ground a shot is fired from the gun which points at the aircraft at an angle of elevation Ѳ. If the initial velocity of the bullet is KVsecѲ [k >1], and Ѳ =tan inverse[...
41. ### Need help with projectiles initial velocity using height and distance

home run that was estimated to have landed 180 metres from the home plate and to have reached a height of 21.3 metres. Calculate the initial velocity of the ball. u^2=v^2-2as t=? u=? v=0 s=180 a=g= -9.8 u^2= √0^2-2x-9.8x180 u= 59.9 m/s am I using the right equation for...
42. ### Projectiles Question -- Tiger Woods drives a golf ball on the Moon

Homework Statement As part of a NASA experiment, golfer Tiger Woods drives a golf ball on the moon, where g = 1.60 m/s2. He ‘launches’ a golf ball with a speed of 285 km/h, at an angle of 42o with the horizontal. What horizontal distance will his drive travel before landing back on the...
43. ### Falling Elevator - Projectiles

What would be seen if a ball were projected at an angle to the horizontal in a falling elevator? Would the path be parabolic as always? And why?
44. ### Upward Moving Projectiles - determining change in time

I have been asked to determine the length of time the ball will be in the air. I understand the basic concept, but the execution is tripping me up. It has been years since I have done a math course, and this is my first foray into physics, so I am a bit rusty. :) A ball is thrown upwards at a...
45. ### Newton's first law and projectiles questions

I just don't get these questions...please help. () are what I think the answers are but I am not positive. Question set 1: Beginning from rest, Mia Edwards runs the 200 meter dash with an acceleration of 0.9 m/s2. 1. define inertia. (inertia- the tendency of an object to resist change)...
46. ### Projectiles Honors Homework: Find Time, Horiz Dist, Vel at Impact

Homework Statement An arrow is fired from the top of a 60 m high cliff. It is fired at 80 m/s at a 30 degree angle above horizontal. a)Find the time of the arrow's flight from start to impact. b)Find the horizontal distance the arrow travels. c)Find the velocity of the arrow(magnitude...
47. ### Projectiles motion problem

Homework Statement A baseball player leads off the game and hits a long ball to right field. The ball leaves the bat at an angle of 30.0o from the horizontal with a horizontal velocity of 40.0 m/s. How far will it travel in the air? 2) person throws bottle straight up in the air at...
48. ### Projectiles - person kicks a soccer ball at an angle

Projectiles -- person kicks a soccer ball at an angle Homework Statement a) A person kicks a soccer ball at an angle and sends it in the air. What angle of projection between 0 and 90 degrees produces the greatest initial vertical component? Greatest intital horizontal component...
49. ### Projectiles launched from platforms of different elevation.

1."A ball is kicked from a platform 3.2m above the ground at an angle of 20 degrees above the horizontal. If the ball lands on the ground 100m away, what is the initial velocity of the ball?" There is no air resistance acting upon the ball and we have to use constant acceleration equations...
50. ### Projectiles and Vectors Graphs

I have a theory question I was wondering about. Today we learned that on a graph of projectile motion, velocity always acts tangent to the graph of the projectile. Why is is this? Also, does acceleration always act down on a projectile? How do acceleration and displacement vectors act on a...