What is Falling object: Definition and 174 Discussions
In Newtonian physics, free fall is any motion of a body where gravity is the only force acting upon it. In the context of general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on it.
An object in the technical sense of the term "free fall" may not necessarily be falling down in the usual sense of the term. An object moving upwards might not normally be considered to be falling, but if it is subject to only the force of gravity, it is said to be in free fall. The Moon is thus in free fall around the Earth, though its orbital speed keeps it in very far orbit from the Earth's surface.
In a roughly uniform gravitational field, in the absence of any other forces, gravitation acts on each part of the body roughly equally. When there is no normal force exerted between a body (e.g. an astronaut in orbit) and its surrounding objects, it will result in the sensation of weightlessness, a condition that also occurs when the gravitational field is weak (such as when far away from any source of gravity).
The term "free fall" is often used more loosely than in the strict sense defined above. Thus, falling through an atmosphere without a deployed parachute, or lifting device, is also often referred to as free fall. The aerodynamic drag forces in such situations prevent them from producing full weightlessness, and thus a skydiver's "free fall" after reaching terminal velocity produces the sensation of the body's weight being supported on a cushion of air.
I got to the quadratic equation of the motion where: 4gt^(2) - g(delta t)t - g(delta t) = 0 and tried to solve for t. In this case, we would take the positive discriminate since we are dealing with the passing of time.
t = ((sqrt(17) g(delta t)) + g (delta t)) / (8g)
However, this is the...
So I have 2 Points P1 and P2. P2 is the center of mass which has an X and Y coordinate. P1 is where I think that it will fall over from and only has an X location.
Now what I want is to find a way to get how far the angle at P1 will change in relation to where these points are within a given...
Hi,
I'm looking at the forces exerted onto an anchor point when a n object is dropped but is secured to that anchor point witha steel wire rope lanyard.
i can find this but not sure if it is relevant or not to my investigation:
Fmax = mg + sqrt(2mg x E x A x fall factor +(mg)2 )
The mass is...
Is there any formula for underwater falling sphere which can measure the velocity of that sphere at any time before it reaches its terminal velocity? A sample question is: I dropped a sphere into water with 0m/s initial velocity. what will be the velocity of that sphere after 3s? {the radius and...
Summary: I am looking to determine the velocity of a the gust of air normal to a falling object. Say if you to be standing next to an open frame building with a flat roof then take away all the columns and let the roof free fall. What kind of wind velocity would you experience.
I am looking to...
Homework Statement
The final velocity of an object falling through air from various heights is given. From this, can you derive an equation for the drag force acting on the object with respect to velocity?
Homework Equations
Maybe relevant?
Wno drag$$=mgh,$$
Wreal$$=\frac{1}{2}mv^2,$$...
Today I was thinking how would I calculate the amount of force I would experience if I were to jump out of a second floor building in the event of a fire and if I had to jump how much force would be applied to me? I was able to find the height of the building by dropping an object from rest out...
Homework Statement
"A falling object travels one-fourth of its total distance in the last second of its fall. From what height was it dropped?"
Reference: Up is (+)
Scenario 1 (Complete motion)
a = -9.8
v1 = 0
d = -x
v2 = ?
Scenario 2 (Motion at the last second)
a = -9.8
d' = (1/4)(-x)
t' =...
If I was attempting to calculate the amount of energy transferred as heat to an object free-falling in the atmosphere, is this how I could go about it?...
Work = (Drag Force) x (Displacement through atmosphere) = Energy transferred as Heat
I am attempting to solve a hypothetical question...
Homework Statement
The reason why the heavy stone and light stone fall equally because of the ration of force to mass is same. can you explain it please what is ratio of force to mass is same?.
Homework Equations
F=ma and F=Gm1m2/r²
The Attempt at a Solution
As their acceleration is same...
If an object with 1kg mass falls free (no air drag), from 100 meters high, and the gravitational acceleration is 9.81, then the mechanical energy will be: 1*9.81*100 = 981 joules.
The work the gravitational force does on the object will be: 9.81N*100m = 981 joules.
Another object with same...
Homework Statement
Estimate the time between each photoflash of the apple in Fig. 2-18 (or number of photoflashes per second). Assume the apple is about 10 cm in diameter. [Hint: Use two apple positions, but not the unclear ones at the top.]
Homework Equations
All we have learned in class is...
Hello,
I found a derivation on NASA and several others that say something different. Can someone tell me which is correct? They differ by a factor of 3. This is confusing because some places say an object falling from 100m should deflect by 3cm but NASA says .16mm. Those are more different...
Homework Statement
[/B]
A small steel-bearing falls 25.0 cm in glycerol in 23.8 s and the same distance in castor oil in 15.1 s. The densities are for glycerol 1260 kg m−3 , for castor oil 961 kg m−3 , and for steel 7830 kg m−3 . The viscosity for glycerol is 1.490 Pa s. Calculate the viscosity...
Well, first of all i want to apologize about my english skills hahaha
I have been trying to calculate a time formula for free falling object through large distances (or weak gravitational fields) and my results don´t have much sense (I test my results in a quite realistic game called Algodoo)...
1. Question
Given an idea spring with constant K, a mass of M is dropped onto the spring from a height of H1. The spring compresses D distance.
We take the mass off, and drop the mass again at a height of H2, where H2 is significantly greater than H1. This time, will the spring compress a...
Homework Statement
Marian, who is standing on her balcony, is surprised by a pigeon and throws a flowerpot up in the air at 2.1 m/s. It takes 3.0 s for the flowerpot to smash to the ground. The flowerpot experiences acceleration due to gravity of 9.81 m/s [down].
a) How high is Marian’s...
Hello,
I am building a bicycle with suspension on it. The rear wheel is connected to the bike via an axle on a swing arm (a long lever), connected to a linkage lever which is connected to a shock, which has a spring on it. Ultimately I'm trying to calculate the force applied to the shock...
Homework Statement
I am trying to develop simulation for a falling object subject to air resistance. Object is similar to Samara seed. object is considered to be under steady vertical descend.
know variable :
surface area of object (A)
weight of object (W)
cd: drag coefficient
object rotates...
Hi All,
Long time absentee from the forums hoping for some direction in my new research.
I've been tasked to look into the stages of motion of objects (dropped from various heights), hitting a body of water (of various depths) and eventually hitting the seabed (of various sediment types). I am...
Homework Statement
Consider a particle in a gravitational field that is also subject to a resisting force proportional to the velocity squared ( Fdrag = + or - cv2).
a) Find the terminal velocity, vT, for the object as it falls.
b) Show that for an object dropped from rest that the velocity...
I don't understand what are the causes of the Coriolis effect for objects moving with respect to Earth. For istance consider an object free falling on the Earth from an height h. Its tangential velocity its greater than the velocity of an object on the surface of Earth, hence it moves eastward...
Homework Statement
I am doing a project on pressure sensitive films and finding if they indicate the correct amount of impact. I have carried out an impact test by dropping a mass of 5KG from a height of 1m. I have calculated the velocity to be 4.43m/s. The kinetic energy just before impact is...
Homework Statement
This is an academic project related to a falling object simulation.
I have come to the point where I'm trying to calculate the per degree angle of the falling object seen in the attached images. The object has known height and length in pixels and is fixed on a pivot...
Hi,
I'm preparing a computer software to simulate the fall of an object for an academic project. The object is rotating (not rolling) over the circular bottom point. I know that the angular velocity at the horizontal point is ω = √(3g/L). I would like to calculate the angular velocity at every...
Homework Statement
"A hot-air balloon is ascending at the rate of 12 m/s and is 80 m above the ground when a package is dropped over the side. (a) How long does the package take to reach the ground? (b) With what speed does it hit the ground?"
Homework Equations
##v_B=12\frac{m}{s}##...
If an object is an infinite distance from a black hole and falls directly to the black hole without being affected by any other force, what is its velocity at the event horizon?
Homework Statement
An airplane flies horizontally with a speed of 300m/s at an altitude of 300m. Assume the ground is level. At what horizontal distance from a target must the pilot release a bomb as to hit the target?
Answer: 2.7km
Homework Equations
a=v/t=d/t2
r_f = r_i + v_i*t + 1/2at2...
Hi guys! So I have been learning about jerk/jolt as the third time derivative of distance, and thinking about Newtons law of universal gravitation, and I have come to the conclusion that a falling object must have jerk, and even jounce. Here's how I came to that conclusion:
The acceleration of a...
So if you have an object in a hot air balloon that it traveling upwards at constant velocity, and this object falls out of the hot air balloon, is its initial velocity 0 or is it the same as that of the balloon?
Thanks in advance!
Have to make a table of measurements, height-time-velocity-acceleration, taken from a free falling object and my professor asked for the acceleration of each trial which is leaving me very confused because I thought g = 9.8ms2 is constant. So I'm going to have to write a bunch of 9.8s or is...
Consider the famous kinematics equations $$x_f=x_i+v_i\cdot t+\frac12at^2$$ My question is: does this equation work for every point A & B along the parabola formed when dropping an object?
Homework Statement
From what I have seen on internet sources, the average force exerted by an falling object on the ground is equal to the work done by the ground to stop the object. Assume collusion is completely inelastic and object sticks to ground after impact.
F: Net force on ground
m...
Hi,
Homework Statement
I'm doing some research into the hydraulic jump and was wanting some help in calculating the impact force.
Hydraulic jump is a phenomenon to do with the turbulence of the water - it is the 'ring' around the stream of water when a tap is turned on
Homework Equations
The...
Hi,
I'm doing some research into the hydraulic jump and was wanting some help in calculating the impact force. The equation I have found to use is:
F = m g h / s
I have the mgh, and was wondering what to use as the slow down distance.
If you didn't know what the hydraulic jump was, it is a...
Homework Statement
Distance from planet = 10^14 meters, Radious of the planet = 10^7 meters, mass of the object = 100kg
g on the planet's surface = 10 m/s^2, g 10^14 meters away from the planets center = 2.5 m/s^2
Homework Equations
Fg=G*m*M/r^2
The Attempt at a Solution
I calculated the...
Homework Statement
In the system shown, the block M (mass of 15.65 kg) is initially moving to the left with a speed of 3.4 m/s The mass of m is 8.26 kg and the coefficients of friction are μs=0.411 and μk=0.304. The string is massless and the pulley is massless and frictionless. How fast will M...
Hi! First post on this forum, though not the first time visiting :)
I am working on a model of an object falling from one layer of air density into another layer with a higher density, effectively changing the acceleration from positive to negative instantly. (Somehow I am thinking of positive...
Homework Statement
An object falls freely, moving 60m in the last 2 seconds. Find the height at which it was dropped.
[/B]Homework Equations
Vf = 1/2(gt^2) + Vo(t)+ Yo
g= 9.8m/s^2[/B]The Attempt at a Solution
the object accelerates at 9.8m/s^2 . and the velocity would be 30m/s. (60 divided...
Homework Statement
A stone is dropped from a bridge that is 65 m high. A second stone is thrown downwards 2 seconds later. Both the stones are heard hitting the water at the same time. The speed of sound is a constant 343 m/s. What is the initial velocity of the second stone.
Homework...
Homework Statement
You will learn a lot about the motion of falling objects in chapter two. At this time you do not have to make any measurements. This exercise is purely numerical. The following table shows the position of a falling apple, in meters, at several instants in time. The clock was...
Hi!
So i have been having this discussion with a friend. we have an old shaft going down about 100meters and we want to tie a 100kg sand bag and use it to generate electricity as it falls. (we will simply pull it back up)
if my understanding is right, then:
i can either generate 980kw for 1...
An object with a mass if falling with a force that is equal to its own weight of 25 pounds. The air resistance causes a decelerate force equal to 1/2 the velocity of the object at any time. If the object falls from rest, what is the velocity of the object after 8 seconds?
I'm just confused at...
I used a ticker to measure to measure the acceleration of falling object. And and now I am writing report about it and the problem is what symbol is used for the marks on the ticker tape? Like for grams (g). What would you use for marks(?) ?
Hello!
I am trying to think of ways to generate significant amounts of heat through the motion of a falling object? Let's say we have a heavy ball and a structure that enables it to fall from a height of 30m for instance, how would you go about creating heat? I suppose you would have to use...
Homework Statement
This is elementary level stuff and I am pretty much past this, and yet I can't seem to find a suitable way of explaining this.I was thinking about Potential Energy of a particle of mass m falling freely under gravity(ignoring air resistance, again, beginner stuff :P) from...
I was reading The History of Physics by Isaac Asimov, and I came across this passage.
"Imagine a body dropped first from a height of 1000 kilometers, then from 2000 kilometers, then from 3000 kilometers, and so on. The drop from 1000 kilometers would result in a velocity of impact v_{1}. If...
Homework Statement
A falling object travels one-fourth of its distance during the last second of its fall. From what height was it dropped?
Homework Equations
none
The Attempt at a Solution
yf - yi = vit + 0.5gt^2
0.25x = 0 + 0.5(-9.8ms^-2)(1)^2
x = 19.6m
Homework Statement
A wet floor sign is pushed on the top and it starts falling. Just before hitting the floor the upper point of the sign sign hit a foot.
The weight of the sign is 5 pounds (2.27 Kg or 22.24 N).
The sign is 2 feet tall (0.61 m).
Homework Equations
With what force and energy...