1
vote
0answers
28 views

What is the angle of projection when at maximum height the speed of a projectile is half the speed at half the maximum height? [closed]

I have been struggling with this problem: The speed of a projectile when it reaches its maximum height is one half of its speed when it is at half its maximum height. What is the initial ...
0
votes
1answer
61 views

Why is the range for a particle thrown at 90 degree same as that of a particle thrown at 0 degree?

There is a derivation given in my book which concludes to the fact that the range is same for two angles of projection, provided they are complementary. I fail to understand this fact. For example, ...
9
votes
2answers
1k views

Put a bullet into orbit around the moon

While I was watching this beautiful video, the absence of air friction pushed me to ask myself: While standing on the surface of the moon, what is the initial velocity by which you can fire a bullet ...
2
votes
1answer
41 views

Distance along projectile motion [closed]

I was doing kinematics these days, projectile motion. And I did the basic concepts: range, max height, time of flight, projectile on inclined plane. I am curious to know how we would solve a question ...
0
votes
2answers
41 views

Time of flight for a projectile with stated initial velocity and size at various distances

I've been mooching round the internet looking for an answer to this one and can't find a ready resource, hence the question. In short, I'm trying to discover the flight time of a shotgun pellet at ...
-2
votes
3answers
92 views

Projectile Motion with air Resistance - Adjust only the Angle to hit a target

OK, let me preface this by saying i am not a physics student, nor have i ever been. I am a software engineer working on a development degree. So this is homework but the assignment was just to create ...
1
vote
0answers
58 views

How to find the force to cause certain trajectory? [closed]

So I got a little board today and decided to do some physics. What I came up with is confusing me alot. Say someone throws a rock and when this happens you get the known's of. From here is there a way ...
1
vote
1answer
75 views

Dropping a ball in a fast moving train

If I drop a ball in a train moving at a constant speed, will it land on the spot I aimed it at or a little away as the train has moved while it was in air? If it lands away, will the observer not know ...
4
votes
3answers
755 views

Ball thrown from a moving train

This is not a question about throwing a ball vertically in a moving train. I am asking what would happen if I throw a ball in a horizontally in a moving train. Assume I am facing an exit door of a ...
1
vote
4answers
103 views

Is it possible to prove that projectiles with drag will not travel in a parabola under the theory of classical mechanics?

Can you prove that projectiles will travel in a parabola, provided the acceleration due to gravity $g$ does not vary significantly along the trajectory? This should take air resistance into account. I ...
1
vote
2answers
67 views

Why is the constant velocity model used in a projectile motion derivation?

I was re-studying university physics last week, I'm now in the chapter about kinematics in 2 dimensions and specifically the one treating projectile motion. In page 86 of his book (Serway - Physics ...
0
votes
1answer
37 views

Kinematics and Energy - Finding the work done in projectile motion

If you are asked to find the work done by gravity on a projectile, the force will obviously be the mass multiplied by gravitational acceleration. What will the displacement be, the horizontal or ...
0
votes
1answer
58 views

Follow up question regarding: Deceleration rate of objects of different mass but the same otherwise

My first question was answered here: Deceleration rate of objects of different mass but the same otherwise . But based on that, here is a follow-up question (I also edited my first post with the ...
2
votes
2answers
59 views

Deceleration rate of objects of different mass but the same otherwise

Using a tennis ball as an example object, if one ball weighs 1 ounce and the other is 2 ounces, and both are struck at 100 mph on the same trajectory, would there be any difference in the deceleration ...
-3
votes
1answer
75 views

Throwing an object in the air [closed]

Studying formulas about velocity and acceleration I came up with a question: if I throw an object in the air with a velocity $v_0$ (suppose i throw it vertically) in how much time its final velocity ...
1
vote
1answer
48 views

Projectile trajectory with linear air resistance [closed]

I have the following equations $$\ x′′(t)=−\frac km x′(t)$$ $$\ y′′(t)=−\frac km y′(t) - g$$ where $k$ is the drag, $m$ is the mass of the object and $t$ is the time. $g$ is the gravity constant. ...
1
vote
1answer
104 views

Tangential and radial acceleration in projectile motion

I'm currently learing kinematics, specifically projectile motion and as an example in my textbook is a bullet fired at some angle. I understand the derivation of formulas to describe that motion and ...
0
votes
1answer
35 views

Doing a spring experiment, and need to find the stretch required

I'm doing an experiment where I have to calculate the stretch of a spring needed for it to launch itself into a trashcan located some distance away. The spring is located on the edge of a ramp that is ...
0
votes
1answer
48 views

Two equations for $y$ in projectile motions

I have two equations on my equation sheet: $$y=v_o t \sin \theta - \frac{1}{2} g t^2.$$ And then another: $$y_{\max} = \frac{v_o^2 \sin 2 \theta }{2g}.$$ I understand that the first one is an ...
1
vote
1answer
45 views

Minimize initial velocity of projectile to arbitrary point

I'm supposed to shoot a projectile from the origin to a point $(x_0 , y_0)$ with minimal initial velocity $v_0$. (no air resistance; regular gravity) The flight time should be $T=\frac{x_0}{v_x}$. ...
3
votes
0answers
59 views

What is the maximum range of a bullet flying through the sky? [closed]

How far would my bullet fly with the following characteristics? 1.2km/second initial velocity 45 degree angle into the sky 'Normal' atmospheric conditions No wind Typical high-powered rifles have ...
1
vote
0answers
41 views

What is the speed of a thrown ball [closed]

I would like to know how much speed is loss when a baseball is pitched. When a pitcher hurls the ball, it must lose speed before the catcher catches it because of the air resistance. So, if the ...
0
votes
2answers
70 views

Ice throw from industrial wind turbine

I was watching a documentary where the residents didn't want to have a wind turbine erected nearby. One of the comments from the company was that an ice throw would have very little importance since ...
1
vote
0answers
22 views

Finding the initial vertical and horizontal velocity [closed]

Basically I need to get an initial vertical velocity to make the ball reach a specific height, but also I need to get a horizontal verlocity so that the ball will travel the distance. For an example ...
1
vote
1answer
100 views

Is speed squared constant?

q. A heavy particle is projected at speed $U$ at an angle $\alpha$ to the horizontal. The particle is subject to air resistance which is experimentally found to vary proportionally to the square ...
1
vote
1answer
224 views

3D ballistic trajectory with quadratic drag. Calculating position and velocity at time $t$

A particle starts at the origin and has an initial velocity represented by a 3D vector. The particle experiences gravity and air resistance with quadratic drag (based on velocity^2). What I've been ...
7
votes
2answers
246 views

Find the minimum value of velocity [closed]

Find the minimum value of the initial velocity $u$ of the particle such that the particle crosses the wheel of radius $R$. Details and assumptions $R=2m$ $g=9.8m/s^2$ Neglect air resistance. All ...
0
votes
1answer
43 views

Determining the horizontal position of an object [closed]

In my calc-physics class we were given the following question: A movie stuntwoman drops from a helicopter that is $30.0 m$ above the ground and moving with a constant velocity whose components are ...
0
votes
2answers
85 views

How can I calculate the initial velocities of a set of objects with a consistent force?

I'm trying to figure out which object would have the largest time of flight when launched from a slingshot. To do this, I need the initial velocity. How can I calculate this if I know the mass and ...
0
votes
2answers
100 views

Maximum range for projectile thrown from a mountain [closed]

I have doubts with the following problem: A projectile is fired from the top of a mountain that has a downward slope with angle $\phi$ from the horizontal. The initial velocity of the projectile is ...
0
votes
2answers
122 views

Problem with horizontal projectile motion questions

I don't really understand horizontal projectile motion. Suppose I throw a ball horizontally. Given $\theta$ = 0 degrees, time = 0.5 seconds, horizontal range = 15.5 metres, the "initial horizontal ...
1
vote
0answers
283 views

Numerical solution of two coupled second order differential equations of motion [closed]

Is there a numerical algorithm for solving a pair of coupled second order differential equations? This question arises from a homework problem that I have that involves two dimensional projectile ...
1
vote
0answers
61 views

Bullet energy loss in solid materials [closed]

Does someone know simple model of energy loss in solid materials for a solid bullet? For example: I want to estimate momentum transferred to a thin plastic plate given by a small bullet. No matter ...
0
votes
2answers
896 views

How to plot $(x,y)$ coordinate of projectile motion (with air-resistance)? [closed]

I am trying to plot a graph to show the difference in projectile motion when it has air-resistance and when it doesn't have air-resistance. I set the mass, $v_0$ and $\theta$ as constant I can plot ...
0
votes
0answers
48 views

Modeling with First Order Equations [closed]

A ball with mass 015kg is thrown upward with initial velocity 20m/s from the roof of a building 30m high. There is air resistance of magnitude v^2/1325 directed opposite to the velocity , where the ...
0
votes
1answer
62 views

Earth's graviational pull at the centre [duplicate]

Suppose, I somehow happen to dig a hole diametrically through the Earth (neglecting all constraints like molten core etc ) ... and I throw an object from one side of the hole, will it reach the other ...
0
votes
1answer
60 views

Some subtleties in direction of drag force

Consider a body released from a height $h$ and assume a drag force is linearly proportional to the velocity. Then by Newton's Second Law, $$m\mathbf{\dot{v}} = \mathbf{F_g} + \mathbf{F_{drag}} = ...
0
votes
1answer
282 views

Calculating angle of projectile motion [closed]

I realize that similar questions have been asked but I'd like to put my problem here and what I have to make sure everything is right. So my problem is: I've got a rock $2.5$ meters above the ground ...
0
votes
1answer
112 views

Parametric equations in ballistics

while studying some material on ballistic trajectories (the basic gravity-only parabola), I've tried to come up with closed-form expressions for another case, where in addition to gravity we add a ...
2
votes
2answers
162 views

Projectile motion maximum distance to origin

Is there an elegant or easy way to derive the maximum distance from the origin to a point of the parabola created by projectile motion (assume initial position is the origin)? Other than ...
7
votes
3answers
1k views

Why does tossing a coin in a train and on a train differ?

Suppose that I am inside of a moving train. I have a coin in my hand and I am standing still. If I toss this coin straight up, it will fall back into my hand. Now, suppose that I am on that moving ...
0
votes
0answers
62 views

Estimating elevation by camera angle

I'm reading this tutorial on kalman filters, Section 7.2, pg 85-86. It reads as follows: You spotted an enemy mortar installation about thirty kilometers away, on a hill that looks about 0.5 ...
0
votes
2answers
238 views

Finding the optimal angle of a projectile motion [closed]

I am trying to solve a task in which I need to calculate the optimal angle($\alpha$) with which the projectile will land the furthest from a height ($h$), so what I basically have is the equations for ...
4
votes
3answers
144 views

Do bullet/gun physics change if the gun is traveling very fast?

If I'm running at say $400\: \mathrm{m/s}$ and a bullet travels at $400\: \mathrm{m/s}$ and I fire the gun, will I see the bullet leave the barrel? I either see it stay in the barrel floating ...
0
votes
2answers
73 views

Relative motion question [duplicate]

I'm sitting on my seat in a train and the train is moving at a very high speed, let's say 600 mph. If I throw a ball vertically up in the air (while still sitting on my seat), will the ball fall back ...
12
votes
2answers
637 views

Throwing a ball upwards in an accelerating train

If I throw a ball upwards to a certain height in an accelerating train, will it end up in my hand? At the moment I release the ball, it will have a velocity equal to that of the train at that instant. ...
2
votes
1answer
162 views

Is there a better, faster way to do this projectile motion question? [closed]

The question is In a combat exercise, a mortar at M is required to hit a target at O, which is taking cover 25 m behind a structure of negligible width 10 m tall. This mortar can only fire at an ...
0
votes
2answers
155 views

Under what conditions, will a projectile motion follow a half circle?

What came to my mind is to throw an object far from the earth with a particular speed equal to $$V_{sat}=\sqrt{\frac{G\times M_{central}}{R}}$$like satellites. However, it would follow a full circle.
4
votes
2answers
148 views

Does $y$-motion really have nothing to do with $x$-motion?

I am watching a Physics 1 for physical science majors on coursera.com, and in one of the concept tests there is a question that goes like this; "A bullet is fired horizontally from a rifle on the Moon ...
1
vote
1answer
179 views

Math / Physics Help - Barrel Pressure and Velocity

Back in 1993 I derived the following equations to calculate projectile velocity and barrel pressure. Recently, I have noticed that I need to double the calculated results in order to obtain real word ...