What is Projectile: Definition and 1000 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. G

    I Range of projectile launched from a non-rotating spherical planet

    I figured this would be a problem in some classical mechanics book but so far I can't find an answer anywhere. Assume there is no drag or lift, and since the planet is not rotating we don't have to worry about Coriolis effects. I'm working on a solution but I want to see if my work is correct...
  2. hello478

    Vertical displacement with time of a projectile

    my answer was D, which is correct considering the motion downwards eg, object thrown from a cliff but what if an object is moving up?like a football being kicked? i cant understand how this graph applies to that...
  3. hello478

    Arrow being fired to centre of target

    i solved it like this... s = ut + 1/2 at^2 t= 1.08 (from part a) u= 65 sin4.30 a= 9.81? or -9.81 the answer said -9.81 why? wouldn't acceleration change from -9.81 to +9.81 because it moves up then down??? its soo confusing...
  4. Bling Fizikst

    Particle projected from above a dome

    Since the ball will follow a parabolic trajectory , i threw it into the coordinate plane with particle starting from the origin . $$y= kx^2$$ Differentiating wrt ##t## : $$ gt=2ku^2 t\implies u=\sqrt{\frac{g}{2k}}$$ where $$k=\frac{\sin\theta}{R\cos^2\theta}$$ Now , final speed when it reached...
  5. GinaMitchell

    Engineering Science Fair Air Cannon Help

    Hi - I built an air cannon to launch a fishing lure for my science fair project. The air cannon launched a 1/4 oz lure 31.4 meters. Based on this, I calculated the initial velocity to be 17.54 m/s using the formula for range of a projectile. I want to be able to launch the lure 38.5 meters. I am...
  6. R

    A ball is thrown w/initial speed vi at an angle 𝜃i with the horizontal

    A ball is thrown with an initial speed vi at an angle 𝜃i with the horizontal. The horizontal range of the ball is R, and the ball reaches a maximum height R/8. In terms of R and g, find the following. (a) the time interval during which the ball is in motion: Sroot(R/g) Correct (b) the ball's...
  7. J

    I Why do bullets precess in the opposite way from gyroscope diagrams?

    1) Bullet spin causes a bullet to become a gyroscope. Specifically, bullets have their center of pressure in front of their center of mass. Therefore, when pressed, gyroscopic forces cause a bullet to spin 90 degrees instead of tumble. See this diagram: 2)The precession does not cause the...
  8. SSKscioly

    Help with science project to launch a projectile

    TL;DR Summary: Hi, I am a high schooler competing in a science competition building a trajectory to shoot the projectile similar to the one in the thread below. https://www.physicsforums.com/threads/aarons-gravitational-potential-energy-to-launch-projectile-science-competition.773745/ The 4...
  9. G

    I Railgun: Significant magnetic field where projectile is?

    Hi. Very simplified schematics of railguns all look like this: I have trouble properly understanding this. So apparently there is still a significant magnetic field where the projectile is, even though that's where the current stops flowing through the rails? Of course the magnetic field...
  10. James1019

    Projectile motion only provided acceleration diatance

    TL;DR Summary: Find initial vertically upward speed of the ball Find horizontal speed of the speed Find angle How to: Find initial vertically upward speed of the ball Find horizontal speed of the speed Find anglei try to solve it but it didn't work
  11. James1019

    Projectile motion when only given distance and acceleration

    TL;DR Summary: Find horizontal velocity? I have no idea how to solve the problem, the question only provide distance 16cm(h),3.6cm(v) and acceleration = 0
  12. kuruman

    Solved problem: Projectile in slanting tunnel

    (a) Find the initial speed. Solution The relevant equations are (4) and (5) derived here and reproduced below as (1) and (2) respectively: $$\begin{align} & \frac{\Delta x}{\tan\!\theta-\tan\!\varphi}=\frac{2v_{0x}^2}{g} \\ & \tan\!\varphi=\frac{1}{2}(\tan\!\theta+\tan\!\omega)...
  13. C

    Finding the launch angle for a projectile if the range is 3x the max height of the trajectory

    For this problem, The solution is, I don't understand how they got from ##\frac {sin^2\theta_i}{sin2\theta} ## to ##\frac{tan\theta_i}{2}##. Would somebody please show me the immediate steps? I also don't understand is why they say the ignore the trivial case where ##\theta_i = 0~rad##...
  14. themethetion

    Projectile Motion Using Vectors

    TL;DR Summary: Using vector functions how can I find the minimum average velocity (something greater than 11.86m/s) of a ball if the launch angle is unknown and if I have a point that the object must travel through (11.86, 3.47)? In my assignment, I developed a function for a lob shot...
  15. DioMiner

    Why does this not work? Projectile Motion problem for Dynamics Class

    TL;DR Summary: I want to mainly figure out where in the problem solving I went wrong. I understand the correct answer (since I looked it up), but to me, it does not make any sense. I am honestly stumped at this point. Online solutions say that my equation y = 0.5774x-0.003354x^2 should...
  16. A

    Finding velocity for projectile given distances and launch angle

    i used t=d/v for the x direction using the formula t=250/vcos55 and subbed that into the formula for the y direction d = (v) (t) + (0.5) (a) (t)^2 35 = (vsin55) (250/vcos55) - (4.9) (250/vcos55)^2 canceled out the first two v 35 = sin55 (250/cos55) - (306250/v^2cos3025) 35 = 357 -...
  17. Kaiser98

    Projectile motion problem – determining initial velocity of throw

    My reasoning was to use this kinematic equation to first get time of flight of the baseball using horizontal components, and then use this same equation again to find initial velocity.
  18. Curiosity_0

    B Time for which a vertical projectile stays motionless in midair

    We know that if a projectile is thrown vertically, there will be a brief time when it momentarily stops. Can we calculate this brief moment?
  19. Argonaut

    Projectile Motion on an Incline

    I worked myself into a trigonometry rut. I've tried two approaches, first by not changing the frame of reference, and second by taking the incline as the horizontal x axis. Here is my second attempt: Take the incline as the horizontal. Then the coordinates of target T are: $$ \begin{align} x_T...
  20. dejavu333

    Projectile Launch Angle: What Could Be Causing My Arccos Computation Problem?

    if the target is lower than me, the formula is below, but if it's higher as in the task, a whole different formula is required I think. a = 9.8 * distance^2 / velocity^2 phi = Arctan(distance / height_diff) angle_if_elevation = ( Arccos((a - height_diff) / Sqroot(height_diff^2) + distance^2)) +...
  21. G

    Find v_1 for projectile using start position, final position and angle

    I have attempted the problem a few times, and have posted my work below. I thought to check my work using ## v_x t = v_1 \times \cos\theta \times t = \Delta x## to see if I get back expected results, and I did for the horizontal motion (the substitutions are from the numbered steps below): ##...
  22. G

    Projectile motion when kicking a ball that lands on an upward slope

    We know x = R =max range (28m) on level ground. Need to find v()^2. Subbing y=0 into (1) above, get v(0)^2 = (gR^2/)/(2*cos (theta)^2 * tan (theta). ... (2) This didn't seem right, since this means v(0)^2 is a negative number ... maybe my orientation or algebra wrong? Anyway, didn't see...
  23. trryan5

    Find Projectile Flight Time Given Only Maximum Height

    I've been trying some online projectile problems. Specifically, I was using this one on master difficulty, looking at row e. It uses a random number generator; I shared the data I received in the Homework Statement above. According to the help section, you can solve this with the formula...
  24. U

    Golf Ball Projectile Motion Problem -- Solved

    26.6m/s = v0 36.5º = θ g = 9.81m/s^2 A) Find Range: (v0^2)/g *sin2θ = (26.6^2)/9.81 * sin2(36.5) = 89.99 I double-checked with the other Range equation (2v0*cosθ * (v0sinθ)/g) so I know I'm doing something wrong. Please help! Thank you edit: A) Correct answer is 69.0
  25. G

    Projectile Motion of motorcyclist

    I assumed the cyclist was going 60-kph. Then worked backwards as shown above to calculate the deceleration in the x direction and then the time to decelerate to a stop at 39 m. Then used this time to calculate the initial speed if cyclist thrown 39 m, which was 8.4 m/s. But if he was going...
  26. jk185

    I Coriolis acceleration of a projectile launched at the equator

    I have a question about the Coriolis acceleration experienced by a projectile launched from the surface of a rotating body. Say a ball is launched at 45 degree angle relative to the surface at some initial velocity v0. Let's further specify that the ball is launched due north from the equator...
  27. X

    Launching a Projectile with Air Resistance

    Mentor note: Moved from a technical forum section, so Homework Template is not present. Hello Physics Forums members, I am a student in AP Physics C and I was just working out the range of a projectile when air resistance is non-negligible. As of right now I'm going to use the linear model of...
  28. GopherTv

    B Calculating the Distance that a Catapult can launch a Projectile

    I know the spring constant of my spring, 90.54 n/m The spring is stretched 13.5 cm Im launching of a deck that is 1.75 meters high
  29. S

    How far will a piece from an explosive projectile fly?

    At first, I want to use conservation of momentum when the object explodes at the highest position but I think the projectile is not a closed system (there is weight acting on it). Tried conservation of energy but not enough information provided. What approach should I take for this question...
  30. C

    Velocity Formulas for Projectile Motion

    Hi, so I solved this using energy. I also tried solving this using kinematic equations. The issue I am running into s for calculating the Vy of the problem. I am able to find the time it takes the rock to fall using d=(1/2)gt^2. Then, I considered two different ways of going about finding the...
  31. C

    Circular motion to projectile motion

    So first I found the velocity of the ball at the bottom of the swing from the force equations, which I got to be 4.9 m/s and this is only in the x-direction. Then using the projectile motion for delta y I found time, which is 0.2s. Then using that time I found the delta x to be 0.98m. I just...
  32. ChichoRD

    Creating an Enemy with 2D Linear Movement: Calculating Projectile Angle

    Hi, I am a game developer and recently found myself in a situation where I wanted to create an enemy that shoots at you given a set of variables. The game takes place in a top down view so there is no need for gravity acceleration, just 2d linear constant movement. The question to answer is...
  33. SayedD

    Olympiad Projectile Problem

    So using the projectile equation I got ##a\sin (\alpha + \beta) = v\sin (\alpha + \beta)t + \frac{g\sin \beta t^2}{2}## To find t we use the other projectile equation: Since the horizontal velocity must be 0 for it to hit the ground perpendicularly we set the equation to be: ##0 = v\sin (\alpha...
  34. A

    B Is Gravity Impacting Projectile Range Beyond Air Resistance Effects?

    Calculated maximum range of arrow at 45 degrees with initial velocity measured horizontally is of course reduced by air resistance. BUT initial velocity at 45 is reduced because propulsive force is constant and gravity reduces velocity by about 3m/sec. So not all distance loss is drag. Authors...
  35. S

    Max initial angle so that the projectile range keeps increasing

    Can I get a hint on how to start with this problem ? Thanks in advance I can't really think of anything...
  36. rudransh verma

    A Projectile problem -- Time to reach 1/3 of the max height

    Assuming it’s one body whose initial speed is u. First it attains height h then H. t1 and t2 are two times at which they attain h and H. ##h=ut1-\frac12gt1^2## ##H=ut2-\frac12gt2^2## ##\frac {t1}{t2}=1/3## Replacing t2 with 3t1, I am stuck.
  37. D

    Maximize Range of Projectile Launched from Cliff

    I found the function of the range of the projectile launched from a cliff. R = vcos(x)((vsin(x))+sqrt(v^2sin^2(x)+2gh))/g I stopped here because I feel like taking the derivative and optimizing for maximum would spiral out of control. Is there another approach to this problem?
  38. GiantYoda

    Kinematic Equations in Projectile Motion (this approach is not working)

    Givens: Vyi=12.5 m/s Vyf=-12.5 m/s (at the same horizontal level) ay=-9.81 m/s^2 Δy= zero m (as the displacement on the y-axis, when the projectile reaches the same horizontal level, is zero m) Δt=? When I use Δy=[(vyi+vyf)/2]*Δt I get the time as undefined. Δt= 2Δy/(vyi+vyf) = 2*0 m/(12.5...
  39. burakyildiz

    Projectile Motion Experiment: Results Too High?

    Hello everyone, I have a homework about projectile motion experiment and I threw small ball over the table and ball did projectile motion at the end of the table and ı recording this motion on motion tracker and motion tracker gave me acceleration of y component of ball as 14.02 m/s^2. But it...
  40. rudransh verma

    Diving airplane as a projectile

    The first part is simple. ##10 secs = 0.0027 hrs##. $$0.7=290\cos30t$$ For the second part $$s=-290\sin30t-\frac129.8(0.0027)^2$$ But I am getting wrong result.
  41. rudransh verma

    Projectile negative vertical displacement

    I know how it’s done. So let’s jump on the question. The displacement that came was negative 6 cm. I want to know how this formula describes perfectly negative displacements. I don’t understand the mechanism. If I assume ##ut## to be distance traveled in absence of g then what is ##-1/2gt^2##...
  42. rudransh verma

    A stone projectile hitting the target

    $$(y-y0)=ut-1/2gt^2$$ $$y= -1/2gt^2$$ $$t^2=-1/98$$ If I get t I will be able to solve for x=ut
  43. R

    Mechanics: calculating launch angle of projectile

    I am trying to find the launch angle ##\theta## using the relationship: ##\theta=\arctan(\frac{v_{y}}{v_{x}})## So, ignoring attenuation due to air resistance, we have a constant horizontal velocity: ##v_x = d_x/t = 95m/4.5s \approx 21 m/s## But what value do we use for ##v_y## which is not...
  44. sauravp

    How to make an accurate and consistent turret for this projectile competition?

    Summary:: What propelling mechanism can get me most consistent shots? Compressed air, spring powered, rubber band powered or any other Hello, I am a high school student participating in a local competition where I have to make a turret. Here are the rules: 1) The projectile has to fall in a...
  45. A

    B Projectile motion — Thinking about forces on a curve ball

    When a ball is thrown such that it moves in a curved trajectory in the horizontal plane, it amuses me to think of its dynamics. In motion of a ball thrown upwards the force of gravity gives it a parabolic trajectory However when the ball is thrown to curve and hit a target, (in the horizontal...
  46. Rubberduck2005

    Tricky conceptual Projectile motion question

    So far all I have determined is the equations of motion for the two and that is as follows. It is trivial that y(t)=v1sin(Q)t -gt^2/2 and that x(t)=v2cos(Q)t. Now the angle that is anticlockwise from the negative horizontal of the robber is 90 - Q using basic trigonometry, using this we can...
  47. R

    Show that a projectile lands at a distance ##R = \frac{2v_0^2 sin \theta cos(\theta + \phi)}{g cos^2 \phi}##

    ##V_x = V_0 cos \theta ## ##x = V_0 cos \theta t## ##V_y = V_0 cos \theta ## ##y = V_0 cos \theta t## ##F_x = m\ddot{x}## ##-mgsin \phi = m\ddot{x}## ##\dot{x} = -gtsin\phi + V_x## ##x = -\frac{1}{2} gt^2 sin \phi + V_x t## ##x = -\frac{1}{2} gt^2 sin \phi + v_0 cos\theta t## ##F_y =...