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

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6
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4answers
2k views

A Basic Question about Gravity, Inertia or Momentum or something along those lines

Why is it that if I'm sitting on a seat on a bus or train and its moving quite fast, I am able to throw something in the air and easily catch it? Why is it that I haven't moved 'past' the thing during ...
31
votes
5answers
10k views

What are the precise statements by Shouryya Ray of particle dynamics problems posed by Newton which this news article claims have been solved?

This recent news article (here is the original, in German) says that Shouryya Ray, who moved to Germany from India with his family at the age of 12, has baffled scientists and mathematicians by ...
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 ...
10
votes
4answers
7k views

What causes a soccer ball to follow a curved path?

Soccer players kick the ball in a linear kick, though you find it to turn sideways, not even in one direction. Just mid air it changes that curve's direction. Any physical explanation? Maybe this ...
1
vote
3answers
2k views

Projectiles and escape velocity [closed]

Q: The escape velocity for a body projected vertically upwards from the surface of earth is 11 km/s. If the body is projected at an angle of $45^\circ$ with vertical, the escape velocity will be? ...
4
votes
2answers
11k views

Equations for an object moving linearly but with air resistance taken into account?

I know (from Kinematics) that for an object moving linearly with an acceleration and without air resistance the following equations can be used to determine v(velocity) or x(position of the object) at ...
9
votes
2answers
3k 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 ...
3
votes
1answer
74k 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 ...
2
votes
3answers
5k 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 ...
4
votes
1answer
653 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 ...
1
vote
1answer
5k views

Maximum range of a projectile (launched from an elevation)

If a projectile is launched at a speed $u$ from a height $H$ above the horizontal axis, and air resistance is ignored, the maximum range of the projectile is $R_{max}=\frac ug\sqrt{u^2+2gH}$, ...
6
votes
2answers
740 views

Is there an intuitive explanation for the Southward force caused by the Coriolis Effect on rotating spheres?

From the Coriolis Effect article on Wikipedia, the following with regard to the Coriolis Effect on a rotating sphere: By setting vn = 0, it can be seen immediately that (for positive φ and ω) a ...
4
votes
2answers
179 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 ...
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, ...
38
votes
6answers
55k views

Could someone jump from the international space station and live?

Felix Baumgartner just completed his breathtaking free-fall skydiving jump from $120,000\,\text{feet} = 39\,\text{km}$ above the Earth, breaking the speed of sound during the process. I was wondering ...
5
votes
3answers
3k views

Finding optimal angle for projectile, taking into account linear (Stokes) drag

If you throw a projectile from the ground at a certain angle, it's not hard to see that, assuming we're in a vacuum, throwing it at 45º from the ground will always make it go farthest before it hits ...
8
votes
3answers
3k views

Intuitive meaning of factor 2 in formula of vertical throw max height $h=v^2/2g$

This is a question about a simple thing. The simplified expression for maximum height in vertical throw is $h=\frac{v^2}{2g}$ , could anyone explain intuitively (analogies are welcome) why there is a ...
4
votes
2answers
2k views

The angle of launching an Angry Bird that will land the bird furthest from the launching point is 45 degrees?

This is a question motivated by Angry Birds. When playing the game, I notice that if the initial velocity is constant, the way to land a bird furthest away from the launching point is by launching ...
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 ...
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 ...
1
vote
3answers
474 views

Coriolis force on bullet vs airplane

Why do airplanes experience negligible Coriolis force while bullets experience the Coriolis force in long range shooting, even though the mass of airplane is much bigger than a bullet?
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2answers
2k 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 ...
1
vote
2answers
248 views

Estimating atmospheric friction by measuring the change in velocity of a ball thrown straight upwards

Imagine I throw a ball straight upwards with some velocity $v_1$, and filming the ball with a camera, I can estimate a velocity $v_2$ (along the same vector) after the ball has moved a distance $D$. ...
1
vote
1answer
849 views

Time of a ball going up and down with air resistance

A ball is shot directly upward, and then it comes back to the place where it was shot. Suppose we have air resistance. Suppose $t_1$ is the time period from the moment that the ball was shot to the ...
1
vote
1answer
3k views

Trajectory of projectile thrown downhill

I'm teaching myself mechanics, and set out to solve a problem determining the optimum angle to throw a projectile when standing on a hill, for maximum range. My answer seems almost plausible, except ...
0
votes
3answers
652 views

Why is the range of a projectile proportional to the square of the initial velocity?

I was watching the MIT lecture about projectile motion and the lecturer asked why $$D=\frac{(v_0)^2\sin(2\alpha)}{g}$$ Why is it $(V_0)^2$ not $V_0$? It is a hypothetical question i know that the ...
25
votes
7answers
3k views

If I toss a coin, vertically, on the surface of Mars, will it land back in my hand?

When I toss a coin in Mars, is the planets atmosphere rare enough that I'd rotate with the planet (at its angular velocity), but not the coin?
4
votes
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 ...
13
votes
3answers
2k 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. ...
0
votes
2answers
3k views

Kinematics - projectile motion on inclined plane [closed]

Well I've tried everything to solve this problem, spent well over an hour, and have gotten no results. A particle is thrown over a triangle from one end of a horizontal base it grazes the top vertex ...
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 ...
2
votes
1answer
95 views

How far will the bullet travel before falling back to earth? [closed]

First, the question: A particular high performance rifle cartridge can be fired with a muzzle velocity of 1200 meters per second. The rifle is pointed straight up. Assuming there is no air ...
2
votes
2answers
236 views

Throwing an object with air resistance

say I were to throw a 1 kg ball vertically upwards 100 m/s, with g=10 and also air resistance $0.01v^2$ . By considering the forces I can determine that the speed at which it lands is less than the ...
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
1k views

How to calculate a firing location from point of impact data?

I would like to know how to calculate the point at which a bullet is fired from a gun given information from the scene where the bullet falls. The scene would contain the point of impact (GPS ...
0
votes
2answers
127 views

How is the uniform gravitational field approximation $F_g\approx mg$ near Earth's surface derived from Newton's law $F_g=GMm/r^2$ of gravitation?

I am really bothered about how we can derive the equation of projectile motion. Suppose a point mass will move in the gravitational field of the Earth according to the equation $$\ddot R ...
0
votes
2answers
234 views

A big cannon to match a ballistic missile? [closed]

During the last years of WW2 the Germans used ballistic missiles V-2 (with payload mass ~1,000 kg) to bombard London, from a distance about 300 km away. Suppose the British could respond by building a ...
9
votes
1answer
4k views

What is the maximum efficiency of a trebuchet?

Using purely gravitational potential energy, what is the highest efficiency one can achieve with a trebuchet counter-weight type of machine? Efficiency defined here as transformation of potential ...
7
votes
7answers
2k views

What happens when the spacecraft velocity equals the velocity at it's exhaust?

So there I was resting me eyes thinking about rocket drives, and what-not. The thought struck me that, perhaps, even before Mr. Einstein interferes with the increasing velocity of the spacecraft Mr. ...
4
votes
4answers
7k 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
4answers
4k views

How Felix Baumgartner has reached the speed of sound quickly

I have watched Felix Baumgartner freefall; but I wonder how Felix has reached the speed of sound quickly, in a matter of some seconds, then we had no idea of its speed? Any explanation please.
3
votes
1answer
170 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
3answers
486 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 ...
2
votes
1answer
134 views

Effect of small changes in atmospheric pressure on open cylinder piston

OK, I'm not a physics student, but I played one for 2 semesters 35 years ago... now I'm a competitive shooter working a theory about why small changes in atmospheric conditions cause our hyper-tuned ...
2
votes
3answers
401 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 ...
2
votes
1answer
414 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
3answers
2k views

In projectile motion, what does it mean for the motion along the $x$ and $y$ axis to be independent?

In projectile motion, what does it mean for the motion along the $x$ and $y$ axis to be independent? This question is referring to the concept of projectile motions.
2
votes
3answers
1k views

What is the general approach to calculating time of impact in 3D?

Given two objects a and b moving at fixed velocities, how would you determine (a) whether they will collide at all, and if so, (b) time of impact? (Let us assume these are spherical bodies each with ...
1
vote
1answer
154 views

What is the point of this type of graph? (Projectile) [closed]

What is the point of graphing vs range, during kinematic motion?
1
vote
1answer
79 views

Falling metal cylinders more devastating than a nuke?

I just saw G.I JOE - Retaliation. In the movie the bad guys (spoiler alert) Could this device cause more destruction than a nuclear weapon? If so, how?