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

learn more… | top users | synonyms (1)

-1
votes
1answer
62 views

Kinematics - When projectile lands at an angle

Question: You are watching an archery tournament when you start wondering how fast an arrow is shot from the bow. Remembering your physics, you ask one of the archers to shoot an arrow parallel to ...
0
votes
2answers
104 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 ...
2
votes
1answer
109 views

Calculating wind force and drag force on a falling object

I'm trying to numerically integrate the motion of an object (say, a falling vertical cylinder). Here, there's a drag force: the wind "acting" on the body (presumably adding horizontal velocity) and ...
0
votes
2answers
120 views

Speed needed to make a car jump from a ramp

(I've posted this question on GameDev and I've been told to ask here so I'm pasting the question) I need to make a car jump from a ramp to another, and I need this to be done using AI so I thought it ...
0
votes
1answer
36 views

Modifying differential equations representing a projectile system to account for an arbitrary force

The following series of differential equations represents a projectile's path when solved (g=9.81): Here is some sample output from this system (with initial values x,y=0, v=1500, theta=1.33): I ...
0
votes
2answers
39 views

How to measure the range of a horizontal projectile?

For an experiment, I'm launching a projectile horizontally to determine the relationship between height and range. Pretty basic stuff. But I'm having trouble coming up with an effective way to measure ...
-1
votes
1answer
70 views

Throwing a basketball. What do I need to consider to hit a target? [closed]

This is a question that's been bugging me for some time now and the physics department at school is closed so yeah. Anywho, my question was, given a ball of mass .76, what forces would i have to ...
1
vote
1answer
45 views

Finding displacement given time with changing acceleration

I'm doing a projectile motion physics assignment, and as part of it, I want an equation that gives the displacement of projectile. The equations that I know are $$s = ut+\dfrac{1}{2}at^2 \quad ...
1
vote
0answers
58 views

How to solve Kinematics: two objects meeting in the air

A water balloon is dropped from the top of a 200m high tower. An alert archer at the base of the tower sees the balloon being dropped, waits for 5s, then shoots an arrow at 40m/s straight up towards ...
0
votes
3answers
131 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 ...
1
vote
0answers
39 views

Projectile Motion [closed]

I've spent some time pondering the answer to this equation, without any success. A cannon is arranged to fire projectiles, with initial speed $v_0$, directly up the face of a hill of elevation angle ...
1
vote
3answers
166 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?
-1
votes
2answers
67 views

Simple projectile motion question that I can't figure out [closed]

My initial choice was B, but apparently that should have been immediately eliminated. I simply found the root of the values squared. I know that horizontal motion would be constant velocity, and ...
0
votes
0answers
55 views

How to make sure projectile does not go through a wall?

I'm struggling with a problem, in which I want to determine initial condition (initial velocity, and angle) given that I know my ball has to reach (final velocity, location), but I want to make sure ...
1
vote
3answers
206 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 ...
1
vote
2answers
675 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 ...
4
votes
10answers
2k views

Why does it take a projectile as long to get to its apex as it does to hit the ground?

I was once asked the following question by a student I was tutoring; and I was stumped by it: When one throws a stone why does it take the same amount of time for a stone to rise to its peak and then ...
0
votes
1answer
43 views

kinematics: parabolic movement [closed]

How does the formula $ax^2$ is affected by the angle and the power of the launch of, let's say, a cannon ball, (regardless of its mass)? I am trying to create a simulation, and everything I have to ...
1
vote
2answers
76 views

Working out velocity (including air resistance) [duplicate]

For my computing project, I am creating a projectile simulator but I cant seem to get my head round the air resistance. I tried by working out the horizontal and vertical velocity by solving it ...
1
vote
2answers
96 views

Uniformly Accelerated Motion question

A ballast bag is dropped from a balloon that is 300 m above the ground and rising at 13 m/s. For the bag, find the maximum height reached. Now the book gives me this answer - $V_i$ = initial ...
2
votes
1answer
203 views

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

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
53 views

Do all thing move against gravity with -9.8 meter per second squared acceleration?

If I throw a ball to height h above the earth's surface and then shoot a bullet that reaches the same height but would there be same quantity of acceleration produced in both?
1
vote
0answers
33 views

A fort is on the edge of a cliff of height $h$. Find the greatest horizontal distance at which a gun in the fort can hit a ship [closed]

A fort is on the edge of a cliff of height $h$. Find the greatest horizontal distance at which a gun in the fort can hit a ship, if $\sqrt {2gk}$ be the muzzle velocityof the shot. Find also the ...
1
vote
0answers
46 views

How velocity progresses over time with a non-constant acceleration? [closed]

A $0.25\text{ kg}$ sphere of radius equal to $0.07\text{ meters}$ is dropped from rest from the top of a building. Granted that it will not hit the ground before, when and after what distance ...
-1
votes
3answers
88 views

Air resistance force [closed]

How do I find the air resistance force and the maximum air resistance force when all I'm given is the mass, terminal velocity, and I know it's falling in quite air? I found a formula online but it ...
3
votes
2answers
129 views

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

Let say a plane flights at 1km/s, shoots a 2kg projectile at 1km/s, so to the Earth, the projectile flights at 2km/s with 2*2*2/2 = 4MJ. The same gun when fixed on Earth, shoots the same 2kg ...
0
votes
2answers
247 views

Why does the angle decrease as height increases in bi-level projectiles?

Not taking air resistance into account. I know that the optimal angle for biggest range on a uni-level projectile is 45 degrees. I also know at, as the starting height of the projectile increases the ...
0
votes
2answers
66 views

Height of building [closed]

How would I find the height of a building? I have been given the initial velocity, the angle at which the object was thrown, and the landing distance. And I was able to successfully compute the ...
3
votes
1answer
119 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 ...
-1
votes
1answer
72 views

Does a projectile always meet a freely falling body when aimed at it? [closed]

When we aim a projectile at a freely falling body why does it always meet it irrespective of the range and speed.
2
votes
1answer
38 views

How do I find the angle with respect to the ground that will cause a projectile launched from the origin to land at the origin? [closed]

Given an arbitrary non-zero constant horizontal acceleration (like a breeze perhaps), how would one find the angle with respect to the ground (x-axis) that will cause a projectile launched from the ...
0
votes
1answer
49 views

Equation for Figuring out the Displacement for a Projectile at an Angle

I'm wondering if anybody can simply tell me if there is a simple formula to solve for displacement when you've been given the launch angle and initial velocity? See; http://is.gd/LpT1EA To some, it ...
-1
votes
2answers
64 views

How to eliminate variable $t$ from the equations to solve this question? [closed]

A ball rolls horizontally off the top of a stairway with a speed of $1.52~\text{m/s}$. The steps are $20.3~\text{cm}$ high and $20.3~\text{cm}$ wide. Which step does the ball hit first? I tried ...
0
votes
0answers
90 views

Why golf balls travel faster if they spin?

From the book I have been given to read I found that balls spin due to the centripetal force but i am confused about how exactly do the resultant force causes it to spin and move forward about the ...
1
vote
1answer
123 views

Modeling the motion of a bouncing ball

I'm writing a program that displays a line of text, and animates a ball that bounces from syllable to syllable (like a sing-along). The program knows the location of each syllable, and it knows at ...
2
votes
0answers
67 views

How can we theoretically calculate the number of balloons needed to stop a bullet?

After watching this video, I am interested in proving it mathematically. The problem is that how can we apply the conservation of momentum here to find the velocity of the bullet while we don't know ...
0
votes
2answers
245 views

What would happen if you dropped iPhone from Outer Space? [closed]

I read this article where the title suggests the iPhone was dropped from space, but it looks more like it was dropped from an airplane I would think that if astronauts dropped an iPhone from space ...
0
votes
2answers
174 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 ...
0
votes
3answers
91 views

Reason for motion after terminal velocity

Let some object hang by a string. So no motion since weight was counter balanced no net force. Now string is cut. Object is falling under gravity and experiences air resistance. Terminal velocity is ...
3
votes
1answer
51k 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 ...
0
votes
1answer
2k views

Vertical motion initial velocity given max height

I'm having a hard time finding a formula that calculates the initial vertical velocity for a projectile that should reach a certain height. I'm using this formula to calculate both vertical and ...
4
votes
2answers
2k views

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, ...
0
votes
4answers
2k views

When does acceleration due to gravity equal positive/negative? [closed]

For example a projectile is launched at an angle. What would $a$ in $y=vt +.5at^2$ be? Let's say I choose up to be positive. How do you not confuse yourself whether to use positive or negative $a$?
3
votes
4answers
4k 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 ...
-2
votes
1answer
115 views

Projectile at an angle. Finding the angle using conservation of energy [closed]

Ball is thrown at an angle α and at the highest point it's potential and kinetic energy are the same. Find the angle. Use the law of energy conservation. What the professor wanted $mV^2/2 = 2* ...
2
votes
2answers
82 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
1answer
82 views

Different results for displacement using different Kinematics equations

We drop an object from a height. It displaces a distance $L$ in the $\vec{y}$ direction. So: $$ L = \frac{1}{2}at^2 $$ Or: $$ v^2-v_0^2 = 2aL \rightarrow L = \frac{v^2}{2a}$$ How much would the ...
7
votes
2answers
2k views

Will a bullet dropped and a bullet fired from a gun horizontally REALLY hit the ground at the same time when air drag is taken into account?

In a world without air, I understand they definitely would. However, with drag taken into account, I think they wouldn't. Since the drag force varies proportional to the square of speed (ignoring the ...
6
votes
0answers
80 views

Why is the splash of water always vertical, no matter in which angle the gunfire hits the surface

When gunfire hits the surface of a pond, the water seems to always splash directly upwards, in 90° to the surface of the water, no matter at which angle the gun is fired. The angle is usually very ...
2
votes
5answers
18k 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 ...