The motion tag has no wiki summary.
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1answer
34 views
Projectile motion: Thrust in x direction = acceleration in x direction? [closed]
I understand that in projectile motion, when an object is solely under the influence of gravity, there is no acceleration in the $x$-direction (with the acceleration due to gravity in the $y$ ...
1
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0answers
21 views
Books describing motion of objects in fluid [closed]
I'm looking for any resources that would help me model the behavior of objects moving in fluid. My end goal is to be able to describe the motion of irregularly shaped objects in a river environment. ...
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1answer
87 views
Acceleration, velocity and speed
It is given that acceleration is constant, so can we infer that average speed and velocity are the same?? Moreover, circular motion is out of the question, as the function of x(t) where ...
4
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3answers
152 views
Does more rain strike a vehicle while moving or while stopped (or neither)? [duplicate]
Assume there is a rainstorm, and the rain falling over the entire subject area is perfectly, uniformly distributed. Now assume there are two identical cars in this area. One is standing still, and ...
2
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1answer
68 views
Convert a 200mm linear stroke into 90 degrees motion
Can anyone help me Convert a 200 mm linear stroke into 90 degrees motion with as much mechanical advantage as possible or into two 90 degrees motions with as much mechanical advantage as possible?
...
1
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1answer
55 views
Fundamental properties of motion
The first paragraph of the Wikipedia article on the angular momentum operator states that
In both classical and quantum mechanical systems, angular momentum
(together with linear momentum and ...
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0answers
23 views
Motion of a particle when acceleration depends on position [closed]
I´m given an acceleration vector in parabolic coordinates which depends on the position
a=F(u,v)u+G(u,v)v
Having all the initial values of the problem, how do i solve for the equations of motion.
I ...
3
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1answer
89 views
Calculating the path of a ball with spin moving across a table
A ping pong ball is rolling over a smooth (but not frictionless) table. During its travel, a clockwise spin is placed on the ball. The ball's path is changed to move to the right (in perspective from ...
7
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3answers
228 views
How do you explain Kepler's third law in general terms without complex math?
I understand the first law-elliptical orbits, and the second-equal area in same time, but I need help with the third one. Note that I am not in an AP course or taking calculus at the moment so simple ...
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2answers
164 views
Whirlpools and Tornados
This may not be a great question. But whenever you drain water, a small whirlpool happens, obviously. This got me thinking...
Can we model tornados with this effect, would it even be beneficial?
4
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3answers
143 views
If an electric car were to drive without having to stop, would the range be greatly affected by the speed at which the vehicle is moving?
Of course aerodynamics factors into this question, and the faster you are moving the more air you have to push out of your way, the more energy you use. But would the difference be only a small ...
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0answers
46 views
Horizontal Displacement - Projectiles [closed]
I am having trouble on what is most likely a fairly basic thing to most of you.
I have a question where I have gathered the following:
Given Values:
...
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0answers
34 views
Special relativity: Related speed [closed]
If a sheep is moving in a velocity of 2mph related to a train, and the train is moving in a velocity of 2mph related to the ground what is the velocity of the SHEEP related to the ground.Is there an ...
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1answer
125 views
Newton first law of motion, braking suddenly in car
While driving down the road, if you hit the brakes suddenly, your body moves forward. Explain the reason for this.
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3answers
185 views
Projectile motion, canon vs cliff
A cannon is placed at the bottom of a cliff 85 m high. If the cannon is fired straight upward, the cannonball just the reaches the top of the cliff.
a) Calculate the initial speed of the cannonball.
...
2
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2answers
156 views
London into Australia in 90 minutes
Me and my friend are having a debate on whether it would be possible for a human to travel at 15,000 miles an hour from London to Australia in the matter of 90 minutes. Would a human be able to ...
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2answers
190 views
What is a natural movement of a ball on a upward curve (the two arrow lines pointing upward) given no external force?
If you drop a ball down a upward curving parabolic ramp, what is the expected movement of the ball? Assume the ball is set into motion with no external force.
Would it go all the way from point A to ...
1
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2answers
113 views
How does this chair move?
I have a chair like this(shown in figure). I was kneeling on the part where we sit. I just gave a sudden push to the part where we rest the back, without moving my legs. I found that the chair is ...
4
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2answers
235 views
Why do cars gain lift while going at a high speed?
I've been researching the physics involved with spoilers and I've just been turning up the same information about spoilers giving the back wheels of a car more traction by acting as an up side down ...
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1answer
252 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 ...
2
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1answer
162 views
How does Boscovich's argument show that force must act at a distance?
Apparently Boscovich's argument shows that force must act at a distance:
But how did the velocity of the faster body come to be reduced from 12
to 9, and that of the slower body increased from 6 ...
2
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0answers
30 views
One dimensional motion with changing acceleration. Falling to a large body from a great distance [duplicate]
Possible Duplicate:
Radial fall in a Newtonian gravitational field
My math and physics are rusty. I am trying to calculate the time an object takes to fall to a large body. Before you ...
0
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2answers
149 views
Understanding the concept of period of motion in simple harmonic motion formula
I have a spring system, whose position equation is $$x(t) = c_1cos(8 \sqrt{2}t) + c_2sin(8 \sqrt{2}t)$$
The textbook says it will have a period of motion of $\frac{2 \pi}{(8 \sqrt{2}t)}$. I ...
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1answer
102 views
Which came first, movement or heat?
According to my measly understanding of the universe, when particles hit one another, some of their kinetic energy is transformed into heat. But when we heat particles (for instance, putting a bucket ...
2
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1answer
244 views
From how deep into space can a human “skydive” back to earth? [duplicate]
Possible Duplicate:
From how high could have Felix Baumgartner jumped without disintegrating like a shooting star?
If a human can skydive from an altitude of 24 miles (39 km), and a ...
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1answer
157 views
Intuition of Impulse Formula $J = \sum F \Delta t$
I understand that
$$\begin{align}
J = \sum F \Delta t &= \Delta p \\
\sum F &= \frac{\Delta p}{\Delta t} \\
&= \frac{mv_2 - mv_1}{\Delta t} \\
&= m \cdot \frac{\Delta v}{\Delta t} \\
...
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0answers
129 views
Motions in Non-inertial reference frames? Reference -request
The course 0.2061 in Aalto University covers motion in non-inertial-reference frame but without examples and without references (examples are outlined only in lectures but I find them very hard to ...
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2answers
406 views
Does uniform circular motion occur in real life in a non horizontal plane?
I have a question about UCM, as I am studying it in my Physics course. I understand that Non-UCM experiences a tangential acceleration component, which is the result of changing speed along its ...
0
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0answers
51 views
How to calculate the necessary force to hold a bearing? [closed]
Assume I have a ball bearing which is holding radial load (gravity load) 100lb. The axial rotation has 500 lbf-in. How I can set up the equations to find out the necessary force to hold the bearing to ...
0
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0answers
124 views
How to calculate acceleration of a falling ball [closed]
If a ball was thrown or fell at an angle, given a starting height, and how far away the ball landed (ignoring air resistance) how would you calculate how fast it was going? (I'm guessing is meters per ...
2
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2answers
898 views
Do the physics in the FlyBoard video make sense?
If you haven't seen the video of the FlyBoard, please have a look: http://www.youtube.com/watch?v=Cd6C1vIyQ3w&feature=youtube_gdata_player
Yes, it's amazing, but do the physics make sense or is ...
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0answers
119 views
Easy question about force on an object [closed]
Please excuse me if this is a basic question, but it has been festering in my head for quite some time.
Suppose you have an object of mass m. We apply a force with magnitude f on the obeject directly ...
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3answers
340 views
Calculate kinematics of body movement from the set of spatial coordinates
Short intro
I have a set of 3D (x,y,z) spatial coordinates of arm movement obtained using motion capture system. The example set of such coordinates looks like this (rounded up):
...
2
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4answers
347 views
Why are objects at rest in motion through spacetime at the speed of light?
I read that an object at rest has such a stupendous amount of energy, $E=mc^2$ because it's effectively in motion through space-time at the speed of light and it's traveling through the time dimension ...
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2answers
162 views
Human Kinematics:Does velocity or acceleration become zero at the moment of changing human limbs' direction of movement?
I need to know the answers to following questions about human kinematics. Can anyone kindly help me with it?
When human moves hand in one direction then suddenly or not changes direction of hand ...
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1answer
83 views
Motion in 1-D Bullet [closed]
A bullet after entering a wooden block at rest covers 30 cm inside it and loses half of its velocity. After how much further distance will it come to rest?
3
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1answer
234 views
Why do wheels appear to revolve opposite to the direction they are rotating?
When viewing cars that are driving along side of us, sometimes their wheels appear to be turning backwards even though they are traveling in the same direction as our car. Why do they look that way?
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1answer
211 views
Relative Speed vs speed of light [duplicate]
Possible Duplicate:
Travelling faster than the speed of light
Someting almost faster than light traveling on something else almost faster than light
I've got two questions which are ...
2
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1answer
58 views
Sunrise time across the globe?
This question is more astronomy related, I started thinking when I heard from one of my friends living in Jiamusi, that Sun rise at 02:00 and sets at 14:00, I know that this place is more near to ...
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0answers
130 views
Meeting Of 2 People On a circular track [closed]
Two persons are running on a circular track either in the same direction or in the opposite direction, indefinitely.
The speed of both of them is given to you.
Speed will be positive in clockwise ...
1
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1answer
115 views
why does perpendicular motion to the direction of someone' s approach does not affect the distance between them
I was reading about the the four turtles/bugs math puzzle
Four bugs are at the four corners of a square of side length D. They start walking at constant speed in an anticlockwise direction at all ...
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2answers
147 views
Motion of a rod struck at one end
Imagine a strong metal rod of uniform density and thickness floating in a weightless environment. Imagine it lies on an X-Y plane, with one end (A) lying at 0,0, and the other end (B) at 0,1. Then it ...
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4answers
357 views
How can/does calculus describe the movement of a particle?
I was talking to Roger Penrose about calculus in the appendix in his book Cycles Of Time and he said I'd need a good understanding of calculus if I wanted to read his book in great depth. He said I ...
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1answer
67 views
Does the movement of things in the universe will cease one day?
To start or change the movement, we need a force. This force, according to Newton's second law, is variation of quantity of motion from the object per unit of time.Therefore, if the variation does not ...
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2answers
156 views
Should the cold drink come out of a free falling bottle with an open lid?
If I hold an open bottle and perform free fall, say sky diving, along with it from, say 10000ft, while I'm holding the bottle vertically upwards should the cold drink come out of the bottle? Kindly ...
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2answers
193 views
Confusion regarding geodesic of thrown ball - curved or Cartesian coordinates?
I'm confused trying to understand what's happening in terms of spacetime geodesics when a ball is thrown and its trajectory plotted, height against time to give a parabola.
I read (from more than ...
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2answers
189 views
Find vector position in time give this graph?
Graph is position x position. There are 3 points, $A$, $B$ and $C$.
$A(0,2)$
$B(4,2)$
$C(6,0)$
Particle travels from $A$ to $B$ and from $B$ to $C$ at constant $v = 2 ~m/s$.
Find vector ...
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4answers
241 views
A person weighing 100 N stands on some bathroom scales in a lift. If the scales show a reading of 110 N, which way is he going
Can someone answer and explain it please.
Here are the options:
Moving downwards and decelerating.
Moving downwards with a constant velocity.
Moving upwards and decelerating.
Moving upwards with a ...
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2answers
484 views
Would this model of a boat move according to Newtons 3rd Law?
If i have a small toy boat with a sail, and i attach a fan onto it, FACING THE SAIL, which runs by solar. Once the fan turns on will the boat move or will it remain at rest. Apparently it wont because ...
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4answers
451 views
How does a train, airplane measure its speed?
I always get the doubt about this. I know that a bike measures its speed based on the motion of its front wheel. So what is the case with train? Is it same principle? Then what about an airplane? Is ...
