# Tagged Questions

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

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### Free fall and projectile motion

I'm wondering if something is falling say from a roof, would the distance it falls be the final $y$ position? Also would all the $y$ components (velocity, displacement) be negative?
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### A ball is dropped from the roof of a building. How fast is it moving after 4.9 seconds? (Absolute value) [closed]

i really need help. A ball is dropped from the roof of a building. How fast is it moving after 4.9 seconds? (Absolute value) in m/s A water balloon is thrown downward from a tall building with an ...
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### Help with Kinematics and trajectory [duplicate]

I am asking this again because it was closed and I didn't receive a response. So a baseball is hit with a velocity of 30 m/s at 42.6 degrees to the ground. A fielder who is supposed to catch the ...
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### Two Dimensional Kinematics and Projectile motion [duplicate]

I have a question. So a baseball is hit with a velocity of 30 m/s at 42.6 degrees to the ground. A fielder who is supposed to catch the ball is smart and knows that he is exactly 8 meters from where ...
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### Can a bullet really fly through space forever?

Some people says that if it would be possible to shoot a bullet so high that it would get over the Earth gravitational pull, the bullet could fly through space forever, because of no deceleration of ...
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### Can a bullet shot through a glass make a clean hole?

One can often see (hopefully only in the movies) that a bullet shot through a pane of window glass leaves a hole in it, but overall the glass is left largely intact. However, a low-speed projectile, e....
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### Horizontal distance covered by an object from an initial height to the ground

We are given: An angle $\theta$ with respect to the ground, its initial height $h_0$ and the final distance $d$. How can we find the initial velocity from this information? I tried a bunch of things, ...
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### Projectile under quadratic air resistance force

So here's the problem background: A projectile of mass m is shot straight up with initial velocity $v_0$ and feels a quadratic air resistance force of the form $F = −kv^2$, where $k ≡ mg/u^2$. ($k$ ...
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### Is this scene from the A Team explainable by Physics?

This scene (youtube link) from the movie The A-team, the four members are in the tank and its falling from the air, they fire the canon and it slows the tank from falling for a moment before falling ...
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### Projectiles Launched at an Angle with unspecified Initial Velocity [closed]

I'm attempting to do my Physics homework, and I did the first one right, but that problem gave me initial velocity. This problem gives me only the angle relative to horizontal and the distance it ...
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If you have a projectile with these variables. $x_0 = 1v_{0x} = 70, y_0 = 0, v_{0y} = 80, a_x = 0, a_y = -9.8$ I know how to plot these points with this equation. $$x = x0 + (v_{0x})t + 1/2((a_x)t^2) ... 3answers 148 views ### Question on acceleration of gravity In pre-calculus last week my teacher explained a scenario in which a man throws a rock down a well and takes 4 seconds for you to hear the rock hit the bottom. How far downs the well? Last years I ... 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, ... 1answer 140 views ### Deviation from 2D trajectory [closed] I need to find out how far a ball is from the predicted trajectory in 2 dimensional space and I know the start and end position of the ball in both dimensions. Along with that I know the initial ... 2answers 867 views ### Kinematic sign convention For example, if I drop a ball from a 50 meters building, then I will consider the ground is 0 meter downward is positive ( which makes gravity positive, downward velocity positive, etc) so ... 1answer 55 views ### related to projectile motion [closed] I was given this worksheet from my teacher and well im finding it really tough so far .. the question below is just crushing my skull .. so i would appreciate it if you guys would guide me through it ... 1answer 122 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, ... 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 ... 1answer 160 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 ... 2answers 2k views ### Find the max projection angle so that distance from point of projection always increases We want to launch a projectile from the surface of earth so that its distance from the point of projection is always increasing. What is the maximum angle of projection for which this is possible? ... 1answer 48 views ### Area covered by particle between it's path and horizontal lines Question: The maximum range of projectile is R and the maximum height attained by the particle is H. If the area covered by the particle between its path and horizontal line is A, then A ... 2answers 532 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 ... 2answers 234 views ### What strategy should I use to approach this problem? If my straight line approximation doesn't work [closed] recently i wrote an assignment in one of the questions i got two different answers for the same question by considering a straight line motion The question was somewhat like this THIS IS A HOMEWORK ... 1answer 327 views ### How to derive this formula? [closed] as far as i know the range of an obliquely projected body which is projected with a velocity of u with some angle \theta with the horizontal under the action of gravity is R=u^2sin2\theta/g by ... 3answers 556 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 ... 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 ... 3answers 3k 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 ... 4answers 167 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 ... 0answers 54 views ### Why is more angular momentum required to stabilize the orientation of a heavier bullet? It's often stated that "heavier" bullets require more "spin" to stabilize vs. "lighter" ones. My question is whether this is really a matter of mass. I'm assuming that the destabilizing forces/... 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? 2answers 78 views ### Isn't this statement regarding projectile motion wrong? Isn't this statement regarding projectile motion wrong? If a body is thrown at an angle to the horizontal with initial velocity u, then displacement of body as a function of time is \vec{s}=\... 3answers 321 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 ... 1answer 400 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 ... 1answer 206 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 ... 3answers 535 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 ... 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 ... 1answer 183 views ### Kinematic, motion in 2D [closed] If the kinetic energy at maximum height is 2/5 the kinetic energy at half the maximum height, find the angle of projection. In other words: K.E. at H(max) = 0.4*K.E. at 0.5*H(max) I got 60 degrees, ... 2answers 164 views ### Projectile motion - ball hit 180m/s at 45 degrees, what is the hang time? [closed] Assuming no air resistance etc, how long is the ball in the air for? This is actually part of a longer question concerning the ball trajectory on different planets but I think there must be an easier ... 1answer 618 views ### Kinematics - angle of projection given relation between speed at highest point and half of that [closed] For a projectile launched from a point on horizontal ground, the speed when it is at the greatest height is \sqrt{\frac{2}{5}} times the speed when it is at half of its greatest height. Determine ... 1answer 2k 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 ... 1answer 132 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$$where k is the drag, m is the mass of the object and t is the time. g is the gravity constant. ... 1answer 2k views ### A ball is thrown up, and a second ball is dropped- what is the maximum initial velocity of the first ball so that [closed] This question only exists in one dimension, the y axis. A ball is thrown upwards with an initial velocity V_o from a roof with height h. One second later, a second ball is dropped from the same ... 2answers 1k views ### Upthrust vs Drag 24: A ball is falling at terminal speed in still air. The forces acting on it are upthrust, viscous drag and weight. What is the order of increasing magnitude of these 3 forces? ... 2answers 599 views ### Tangential and radial acceleration in projectile motion I'm currently learing kinematics, specifically projectile motion and as an example in my textbook is a bullet fired at some angle. I understand the derivation of formulas to describe that motion and ... 2answers 180 views ### When solving kinematics questions, how to find time in air? I was trying to help a friend with this question: A ball is shot horizontally off a cliff. What would happen to the horizontal distance it travels if the acceleration due to gravity were doubled ... 1answer 96 views ### Doing a spring experiment, and need to find the stretch required I'm doing an experiment where I have to calculate the stretch of a spring needed for it to launch itself into a trashcan located some distance away. The spring is located on the edge of a ramp that is ... 1answer 81 views ### Falling metal cylinders more devastating than a nuke? I just saw G.I JOE - Retaliation. In the movie the bad guys (spoiler alert) Could this device cause more destruction than a nuclear weapon? If so, how? 1answer 75 views ### Two equations for y in projectile motions I have two equations on my equation sheet:$$y=v_o t \sin \theta - \frac{1}{2} g t^2.y_{\max} = \frac{v_o^2 \sin^2\theta }{2g}. I understand that the first one is an equation for the height ...
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 $T=\frac{x_0}{v_x}$. ...