Object moving through space due to the exertion of a force.

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4
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2answers
41 views

Will a bullet travel the same after going through 2 substances (in different orders)?

This may seem like a trivial question, however I am a little curious as to whether 'order matters' in the case of this system, or whether you would be able to treat any object as a 'black box' with ...
4
votes
1answer
696 views

If a bullet is fired vertically upwards, when it comes back does it fall to the same spot? [duplicate]

What I'm basically asking is that if a body is projected with sufficiently high velocity so that it doesn't escape from the earth's gravitational field but reaches an appreciable height with respect ...
4
votes
2answers
175 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 ...
4
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2answers
181 views

Kinetics energy with different reference frame (a fighter plane shoots a bullet)?

Suppose a plane flies at 1km/s and shoots a 2kg projectile at 1km/s, so to the Earth the projectile flies at 2km/s with 2*2*2/2 = 4MJ. The same gun, when fixed on Earth, shoots the same 2kg ...
4
votes
3answers
861 views

Why is a gun less accurate when the barrel heats up?

I was out target shooting with a friend of mine, and about 2 hours into it I commented how my accuracy seems to be going down the longer we shoot. He (a fire arms instructor in the Navy, so I tend to ...
4
votes
3answers
371 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 ...
4
votes
4answers
8k views

Catapult vs. Trebuchet

I have been looking at trebuchet designs lately, and I have noticed that most, if not all, have a sling attached to them. Without such a sling, the machine would be a catapult. In terms of the speed ...
4
votes
2answers
889 views

Projectile motion along the earth

Suppose a projectile is launched from the Earth's surface with initial velocity $v_0$ well below speed of light and initial angle $\theta_0$ with respect to the vertical line perpendicular to the ...
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2answers
3k views

Is Magnus effect a corollary of Bernoulli principle?

Magnus effect is commonly explained using Bernoulli principle. However, taking the lift on a rotating cylinder as an example, the velocity difference is caused by the extra work done by the rotating ...
4
votes
1answer
529 views

How does a hollow-point bullet move smoothly through the air, presenting a 'cup-shaped' nose instead of an actual sharp-point to the fluid?

Hollow-point rounds move smoothly through the air when presenting a 'hollow cup-shape' instead of a traditional 'sharp point' to the fluid air. Does this mean the air trapped, and at some assumed ...
4
votes
1answer
722 views

Accelerating onto and over inclined plane

Consider an RC car going off a jump. What angle is optimal to achieve the greatest distance? The height of each jump is the same. The angle of the jump and the related length of the jump changes. ...
4
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3answers
422 views

Explanation of Supplee's paradox

I was reading about Supplee's paradox, which is about whether a relativistic projectile, subject to uniform gravitational acceleration, would float or sink underwater. However the solution of the ...
3
votes
3answers
2k views

Free falling objects

My teacher and I are in the middle of an argument because she says that if you were to drop two objects at the same time and the same height, but with different initial velocities, both of them would ...
3
votes
3answers
2k views

Does wind speed things up or accelerate things?

This question may seem odd, but I can't think of anything better. So I'll go straight to the point. Let's say there's a projectile in air going east, shot at a certain angle, with a certain speed. ...
3
votes
1answer
3k views

How to modify the bullet trajectory based on the ballistic coefficient?

I am new to the physics surrounding bullet trajectory and how it is calculated. I am a software developer and I am working on a ballistics calculator for rifles. I am using wiki for the trajectory ...
3
votes
1answer
76k views

Solving for initial velocity required to launch a projectile to a given destination at a different height

I need to calculate the initial velocity required to launch a projectile at a given angle from point A to point B. The only force acting on the projectile after launch will be gravity – zero air ...
3
votes
1answer
204 views

What is the force required to move a raindrop?

I'm doing some research on how much force is required to move a typical raindrop (assuming that it is falling straight down) off to the side of X distance. This is for a school project on creating our ...
3
votes
4answers
14k views

What is the general formula for a trebuchet?

What I'm really looking for is a formula for a trebuchet that I can input the desired initial velocity after launch and mass of the object, and from that figure out how long the long arm, short arm, ...
3
votes
3answers
4k views

Bullet trajectory at different angles

I've read from different sources (can't find them online) that firing a bullet at different angles from horizontal will result in differing amount of bullet drop. For example, a gun is fired at a ...
3
votes
1answer
165 views

Projectiles on inclined planes with coefficient of restitution [closed]

This is the problem I am currently attempting. So far, I've resolved the velocity parallel and perpendicular to the plane to get, perpendicular: $u \sin \theta$ upon launch and $-u\sin \theta$ on ...
3
votes
2answers
90 views

Minimum initial vertical velocity of a projectile

A basketball is launched by a person with an initial velocity $v$ at an angle $\theta $ from a height $L$ into a basket of height $H>L$ which is a horizontal distance $d$ from the person. ...
3
votes
4answers
349 views

Conservation of momentum in a baseball

Conservation of momentum: A thought experiment. A baseball is placed on top of a baseball holder, the kind used to train young batters. A batter hits the stationary ball perfectly horizontal, sending ...
3
votes
3answers
6k views

Projectile Motion with Drag

The overall goal is to write a Mathematica program that will compute the launch angle that will yield the greatest range with using [RandomInt] function, but I was having trouble with the physics. In ...
3
votes
1answer
5k views

Add air resistance to projectile motion

I am given an initial x and y position and initial velocity and I was asked to graph the trajectory in 1 second intervals. This is what I have so far: If $x_0 = 1, v_{0x} = 70, y_0 = 0, v_{0y} = 80, ...
3
votes
3answers
518 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
641 views

How long will it take for a bullet to reach a Geostationary orbit?

I'm curious to know this. Neglect air friction and imagine a bullet that were shot normal to the Earth's surface, from the Equator. I will have to consider the Coriolis effect and so I expect the path ...
3
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2answers
172 views

Can we deviate a bullet from its target? Did anybody try this?

Can we deviate a bullet from its target? Means by applying any strong field at the target? Is there any technique so far like this!
3
votes
1answer
2k views

The trajectory of a projectile launched from a hilltop

Here is the problem: A boy stands at the peak of a hill which slopes downward uniformly at angle $\phi$. At what angle $\theta$ from the horizontal should he throw a rock so that it has the greatest ...
3
votes
3answers
7k views

Finding the max height of a ball launched as a projectile using work-energy

A ball is launched as a projectile with initial speed $v$ at an angle $\theta$ above the horizontal. Using conservation of energy, find the maximum height $h_\text{max}$ of the ball's flight. Express ...
3
votes
0answers
118 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 5-...
3
votes
2answers
372 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 ...
2
votes
3answers
8k views

Does an object's kinetic energy increase, decrease, or stay constant when it reaches terminal velocity while falling?

Does an object's kinetic energy increase, decrease, or stay constant when it reaches terminal velocity while falling?
2
votes
5answers
24k views

Will a ball thrown straight up in a train land in same spot (in real world)?

I have a question that came up in a discussion with friends. If I throw a ball straight up in an enclosed train car moving with constant velocity, I believe the basic physics books say it will land ...
2
votes
8answers
4k views

Real world examples for projectile thrown upwards or downwards

I am preparing a physics course for high school about projectile motions. If a projectile moves with initial velocity $v_0$ in the gravitational field of the earth, the equation $$ s(t) = 1/2 g t^2 ...
2
votes
2answers
363 views

Parabolic motion and air drag

Are this equations correct, in order to calculate the parabolic motion of an arrow with the computation of the drag with the air? $$ \begin{cases} x(t)=\left(v_0-\frac{1/2C_DA\rho v_0^2}{m}t\right)\...
2
votes
2answers
121 views

Explicit Function for Bouncing Ball [closed]

I was wondering if it's possible (and if so, how would you go about it) to write an explicit function for the position of a ball bouncing as a function of time (assuming a coefficient of restitution 0 ...
2
votes
6answers
181 views

Physical explanation for different angles yielding the same range in projectile motion

It's well known that throwing a ball with a given speed at angles alpha or (90-alpha) will get it to land in the same distance. It's easy to see from the equations, but is there a more physical ...
2
votes
2answers
138 views

Are Fluted Barrels More Rigid Than Standard Ones?

This seems to be quite a debated topic in the shooting community and is something I'm not sure about. A fluted barrel is a barrel that has grooves milled into it to reduce weight, help it cool faster ...
2
votes
2answers
249 views

Time reversal in simple *solution* to equation of motion

Consider the solution to the equation of motion for a particle with a constant acceleration: $$ x(t) = x_0 + v_0t + \frac{1}{2}at^2.$$ If I let $t \rightarrow -t$, then the equation becomes: $$ x(-t) ...
2
votes
2answers
102 views

How to actually account for air resistance?

What's interested me in my studies thus far is that in a lot of beginner undergrad mathematics and physics courses we're often told to calculate trajectories, velocities, etc. by "ignoring air ...
2
votes
2answers
3k views

How do I approach this conservation of energy problem, symbolically

In the absence of nonconservative forces such as friction and air resistance, the total mechanical energy in a closed system is conserved. This is why that when I toss an object directly upwards, the ...
2
votes
2answers
53 views

How can I find the maximum height if I have changing acceleration?

I'd like to find the maximum height that a projectile reaches in motion if I have a non-constant acceleration. How would I do this? What variables do I need to know in order to calculate this? ...
2
votes
2answers
115 views

Mathematics of simplified air resistance

I recently encountered a problem in which when throwing a ball upwards one has to determine whether it goes up or comes down faster when not only was gravity to be considered, but also air resistance ...
2
votes
1answer
156 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 ...
2
votes
1answer
435 views

Math / Physics Help - Barrel Pressure and Velocity [closed]

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 ...
2
votes
1answer
179 views

Is it possible to use a powder-based firearm in space?

A firearm relies upon some kind of explosive powder to drive the slug out of the barrel. My guess however is that in space (at GEO, or higher) a firearm would be unusable due to the extremes of ...
2
votes
1answer
1k 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 ...
2
votes
2answers
349 views

Time variation of the distance between two falling objects [closed]

I have solved this question below from my textbook. My answer differs from the one given in the book. I have tried my best to see where I am wrong. I need your help to find the truth of this question. ...
2
votes
1answer
223 views

Speed of three objects falling with different masses

The following is the problem that I am working on. Three different objects each with mass $m_1<m_2<m_3$ is launched from the same height $h$ with three different angles $\theta_1 < \...
2
votes
3answers
433 views

What decides the velocity of a bullet coming out from the gun?

I was concerned about what determines the speed of the bullet coming out from the gun. Is it determined by the strength of the explosive or how fast does it burn up? For example if we take the same ...