The projectile tag has no wiki summary.
26
votes
6answers
22k 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 ...
8
votes
1answer
1k 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
4answers
477 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 ...
7
votes
1answer
249 views
One strategy in a snowball fight
Here's a common college physics problem:
One strategy in a snowball fight is to throw a first snowball at a
high angle over level ground. While your opponent is watching the
first one, you ...
6
votes
3answers
2k views
Why does a bullet bounce off water?
It is known that bullets can ricochet off a body of water. Is surface tension responsible for this or is this the same behavior we see when an asteroid ricochets off the atmosphere? I don't think ...
5
votes
2answers
160 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 ...
5
votes
1answer
64 views
In tennis, why does topspin serve bounce higher than flat serve?
When receiving servers (while playing tennis), I've noticed that the tennis ball seems to bounce up higher on me when the server uses a topspin serve than when the server hits a flat serve. Why is ...
5
votes
3answers
832 views
Including air resistance, what is the escape velocity from Earth?
Including air resistance, what is the escape velocity from the surface of the earth for a free-flying trajectile?
4
votes
2answers
719 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 ...
4
votes
4answers
2k 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.
4
votes
2answers
104 views
What was the muzzle velocity of a home made gun launch strait in the air if air time was 8.2sec?
I built a potato gun and wanted to calculate the muzzle velocity. I remember from physics that I could run the numbers by calculating time from launch until landing. After pointing strait into the air ...
3
votes
3answers
417 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
396 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
1k 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
2answers
168 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 ...
3
votes
2answers
190 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 ...
3
votes
1answer
211 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 ...
2
votes
8answers
1k 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
$$
s(t) = 1/2 g t^2 ...
2
votes
2answers
169 views
Parabolic motion and air drag
Are this equations correct, in order to calculate the parabolic motion of an arrow with the computation of the drag with the air?
$$
\begin{cases}
x(t)=\left(v_0-\frac{1/2C_DA\rho ...
2
votes
2answers
190 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
1answer
113 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
113 views
Parabolic Motion
I was wondering if I was right about this simple problem:
A projectile is shot at an angle of 37.0° with the horizontal. The velocity of the projectile at its peak height is 16 m/s.
Then I was told ...
2
votes
1answer
11k 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
2answers
865 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 ...
2
votes
4answers
326 views
Velocity of Object from electromagnetic field
I am wondering if someone could provide me with a formula that would tell me at what velocity a projectile can be launched from something using an electromagnetic field. The idea is much like a rail ...
2
votes
3answers
145 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
96 views
How can I modify the bullet trajectory based on the ballistic coefficient? [duplicate]
Possible Duplicate:
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 ...
2
votes
2answers
83 views
Parabolic motion (experiment)
We performed a laboratory, performing six releases of a sphere with angles $15^\circ,30^\circ,45^\circ,60^\circ,75^\circ,40^\circ$ a parabolic movement, took five distances for each angle, the initial ...
2
votes
1answer
124 views
Galilean relativity in projectile motion
Consider a reference frame $S^'$ moving in the initial direction of motion of a projectile launched at time, $t=0$. In the frame $S$ the projectile motion is:
$$x=u(cos\theta)t$$
...
2
votes
3answers
132 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 ...
2
votes
1answer
489 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
2answers
315 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 ...
2
votes
1answer
270 views
Realistic projectile motion
I am working on a project involving a simulation of the motion of a projectile (in 3D) aimed at a moving target. The way projectile motion is analyzed in most introductory physics books is not ...
2
votes
2answers
460 views
Ski Jumper's vertical velocity after 246.5m record?
What would be the vertical velocity of this ski jumper (ski flyer), after he first touches down, after he breaks the record with a 246.5m jump? What g force would he experience as he slows down?
...
1
vote
3answers
111 views
Projectiles and escape velocity
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?
...
1
vote
1answer
1k views
Simple Projectile Motion Question
A volcano erupts 50m below the sea level. A rock leaves the crater at 20 m/s at an angle 30 deg with the vertical line. The rock has a mass of 15kg. IGNORE WATER RESISTANCE. It gets out of the water, ...
1
vote
1answer
232 views
If someone shoots a gun (45 caliber) at someone holding up a table or desk 10 feet away, does it slow or turn the bullet away?
Assume it's a standard .45 caliber handgun. Shooter is 10 feet away, and we hold a desk, mini-table, blackboard, etc on our chests(to protect vitals).
How do you figure out the bullet's decrease in ...
1
vote
1answer
147 views
Work done in projectile motion
A projectile is shot at some inclination to the ground. It falls at another point having R distance from the initial point on the ground. Is there any work done?
If initial velocity vector is $(u\cos ...
1
vote
1answer
114 views
Would a projectile keep going forever in empty space?
Would a projectile fired in space and assuming there were no stars or planets in the way, would the projectile continue on to infinity, since the x-component of the projectile's velocity never changes ...
1
vote
1answer
143 views
Projectile motion in two and three dimensions question?
So I bought this book in the library and physics fascinates me and I found this quote in the book " Galileo has proved that when any effects due to air resistance
are ignored, the ranges for ...
1
vote
2answers
113 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
2answers
117 views
Kinetic Energy of Stone
If a stone is launched upward, of which is subject to gravity and air resistance, which of the following will have a greater kinetic energy? The stone at a point on its way up, or the stone at the ...
1
vote
1answer
133 views
Is it theoretically possible for the orientation angle of a projectile to remain exactly equal to the orientation of velocity?
This question is sparked by my answer to this question: Is this simulation following real physics?
After examining the math, I don't see how it is theoretically possible for the situation simulated ...
1
vote
1answer
177 views
Monkey and tree - projectile motion
The famous scenario: A hunter is trying to shoot a Monkey hanging from a tree. However, this question doesn't mention the monkey jumping down from the tree or trying to escape. (The hunter uses a ...
1
vote
1answer
77 views
What would be the effect of a slant barrel on the trajectory of a bullet?
Let's say I saw the barrel of a gun with a 45° angle, what would be the effect on the trajectory of a bullet fired through that barrel ?
Would the bullet be less stable (I guess), would it make the ...
1
vote
1answer
97 views
Idealized trajectory from sloped surface
I am a GIS programmer implementing a visualization.
I am modeling the idealized trajectory of a particle ejected from a volcanic vent using:
$$\text{distance} = \frac{(v^2 \times ...
1
vote
1answer
423 views
Friction due to air drag at high speeds
I am trying to set up this problem, but I am not sure how to go about doing so. (From University Physics, Young & Freedman):
You throw a baseball straight up. The drag force is proportional to
...
1
vote
2answers
1k 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 ...
1
vote
1answer
732 views
Simple projectile motion problem [closed]
A person wants to throw an object from the top of a tower $9,0m$ high towards a target which is $3,5m$ far from the place where the person is launching the object. Suppose that this object is thrown ...
1
vote
1answer
694 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 ...
