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.

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  1. K

    What is the relationship between gravity and conservation of momentum?

    Hi. I am studying physics on my own from scratch, so far so good, though I've run into this concept I am struggling to understand. If we push a large rock over a cliff, it falls because of the pull of the Earth's gravity on it. This force is its weight and it makes the rock accelerate...
  2. C

    Peak impact force of a falling object

    Hi there, I'm trying to work out how much force is produced if a climber was to fall onto a rope. I do realize that it would depend on the rope and whether it stretched or not but for this case let's just say it does not have any give in it. If I use the example of a climb who weighs...
  3. N

    Falling object in gravitation field

    I am trying to study the motion of a falling body in the earth’s gravitational field however not assuming a constant acceleration. I want to work out the distance traveled in a given time. We know that  a = \frac{{GM}}{{{r^2}}} Likewise, we can calculate that \begin{array}{l}...
  4. S

    Falling object collision question

    Hello, I've been trying to figure out the physica behind a collision of two objects due to the force of gravity. Here's the situation as I'm picturing it: A massive object A is falling due to gravity which impacts a stationary object B being held up by a structure. In this particular case...
  5. C

    Force in spring due to falling object

    Hi, I'm designing a crane that is supposed to withstand forces due to a falling object attached to the crane with a non-elastic cable. I have some troubles to calculate what force that will be due to the falling object. I figured that one way is to simplify this system with a spring with...
  6. P

    Work done on free falling object as function of time

    Hi there everyone, Would like some checking of my work or comments. Would like the work done on a falling mass M as a function of time. To begin, the relation for work as function of distance.. w = Mgx but would like as function of time so substitute x this way, x = (1/2)gt2...
  7. E

    Acceleration of a Falling Object from Average Velocities

    Homework Statement After gathering data via ticker tape, of a falling object, I had the following information: Time (s), Displacement (cm) 0.0 - 0.1 , 6.2 0.1 - 0.2 , 16.0 0.2 - 0.3 , 24.5 0.3 - 0.4 , 33.1 0.4 - 0.5 , 43.0 0.5 - 0.6 , 49.7 The Question: Determine the average...
  8. E

    Matlab help to designing a program of a falling object

    Homework Statement I'm currently new to Matlab and have just started trying to solve a few problems with it. So I have to make a program that will display the results of height and velocity of a falling object, as well as plotting the overall function. My main concern is I am using an...
  9. B

    Equations of Motion for an Object Falling in a Parabolic Bowl

    I have a bowl in the form of a parabola (say y=x^2, motion is in 2d! On the graph of the parabola) and i place an object on the edges of the bowl and let if fall in the bowl. I have gravity, and no friction. My question is plain simple: what are it's equations of motion? I know it has to...
  10. K

    G Force upon falling object on impact

    Hi Guys, I have been asked to find out at what point a measurement device go out of calibration when dropped and express that in a g as in G force. Its been 15 years since I studied physics (for 3 years), I do rememeber a bit but I need some help.. I have the size and weight (mass) of...
  11. P

    Force exerted to a falling object

    Homework Statement A rock with a weight of 120 N free falls from height of 2.00m collides with with Earth and digs 60 mm into it. What is the Earth's average force of resistanceHomework Equations F=m*g => m=F/g m*g*h = 1/2*m*v^2 v=√(2*g*h) The Attempt at a Solution I found the...
  12. V

    Average velocity of a falling object problem

    Homework Statement A falling object moves so that its height x above the ground at time t is given by the following equation: x = 100 m - (4.9 s-2)t2. Find its average velocity from t = 0 t t = 2 s. Homework Equations Average velocity = Δx/Δt The Attempt at a Solution I was...
  13. N

    Momentum of a free falling object

    Homework Statement In a physics exam I have this question: "what is the momentum of the weight force of an object in a free fall relative to its center of mass?" Homework Equations Is my answer right ? The Attempt at a Solution My answer is: "If we try to calculate the momentum...
  14. A

    Velocity of a freely falling object

    Homework Statement A certain freely falling object, released from rest, requires 1.65 s to travel the last 39.0 m before it hits the ground. (a) Find the velocity of the object when it is 39.0 m above the ground. (Indicate the direction with the sign of your answer. Let the positive direction...
  15. I

    Mechanics Problem (falling object)

    Hello, let me start with saying this is not homework but rather a question I have asked myself and cannot seem to solve. Homework Statement Basically this: If a ladder is standing against a wall (both in a 90° corner with the ground) and falls over, what is the approximate speed of the...
  16. P

    How Fast Does a Ball Travel When Dropped from a Height?

    Homework Statement A ball of mass 0.163 kg is dropped from a height 1.89 m above the ground. The acceleration of gravity is 9.8 m/s^2 Neglecting air resistance, determine the speed of the ball when it is at a height 0.997 m above the ground. Answer in units of m/s Homework Equations...
  17. P

    Falling object viscometer non-transparant liquid

    For a coursework, I need to derive the equations behind a viscometer. This viscometer has a free falling object in a non-transparent viscus fluid but it doesn't necessarily need to be the traditional sphere. The restriction only is that the object is connected to a thin stick which is used to...
  18. E

    Waves on water generated by a falling object

    Let an object of mass 'm' and volume 'v' be dropped in water from height 'h', and 'a' be the amplitude of the wave generated. What is the relation between 'a' and 'h'. How many waves are generated? What is the relation between relation between the amplitudes of successive waves?? Assume the...
  19. J

    Momentum conservation - falling object

    If an object falls there are two ways to consider momentum conservation Way 1: The system involves just the object therefore the gravitational force is an EXTERNAL force so momentum is NOT conserved Way 2: The system involves object and earth. The increase in momentum of the object down...
  20. B

    Relationship between the angle and time of a tilted falling object

    Homework Statement find relationship between the angle and time of a tilted falling object Homework Equations any that is applicable The Attempt at a Solution As seen in picture below, and that's what I have done so far. It's a tilted object, only gavity and the support...
  21. S

    How Does the Force of a Falling Object Change Upon Impact?

    F=ma eg, a static bag of a 1kg weight has a force on the table of .98N. if it were to fall, would its force hitting the ground be the sum of the standard g of 9.8m/s+ 9.8t? or do you scrap that idea and use K.E. instead? and also, if it reaches terminal velocity and has an acceleration of 0...
  22. J

    Finding velocity of falling object

    A one meter chain that weighs one Newton sits on a flat horizontal table that is one meter from the floor. The coefficient of friction between the chain and table is 0.15. How much of the chain can dangle off the table until the chain pulls itself onto the floor?If it starts to fall from this...
  23. Y

    Reversal of proper time for a falling object

    Consider the Schwarzschild line element for radial motion only: c^2 d\tau^2 = \left(1-\frac{2GM}{rc^2}\right) c^2 dt^2 - \frac{dr^2}{ \left(1-\frac{2GM}{rc^2}\right)} Solve for d\tau^2/dt^2: \frac{d\tau^2}{dt^2} = \left(1-\frac{2GM}{rc^2}\right) - \frac{dr^2/dt^2}{...
  24. M

    Calculating Falling Object's Time to Reach Ground

    A helicopter is ascending vertically with a velocity of 12.5ms^-1. At a height of 120m above the ground a package is dropped out the door. How long does it take for the package to reach the ground ?. The attempt at a solution I know U = 12.5ms A = -9.8ms V = 0ms S = 120m...
  25. S

    Distance travelled by a falling object

    First Post..hopefully of many! I have to work out the minimum distance a 5.6KG object can fall vertically to 'acheive a force' of 12KG when the object hits the ground. I have no other information and really need some help! P.S. I am not a scientist, simply a confused manager needing a...
  26. Y

    Best way to capture the energy of a falling object

    What's the best way to capture the energy produced by a falling object, and then use that energy to produce electricity for example ? Like for instance, I've been thinking of a kind of water mill where it would be an object falling on the blades instead of water, therefore making the mill...
  27. M

    How to measure and calculate drift of falling object in air

    I was wondering how to calculate the drift of an object that is falling though air. If I know the mass, air density, and velocity of an object that is falling how can I calculate its movement off the center of he drop point. I.E if you looking down on a grid with x and y on the side how many x...
  28. S

    Velocity of falling object from different heights using DE

    Homework Statement Find the velocity of a 180 lb object falling from a state of rest from 5 ft, 15 ft, 25 ft, and 45 ft Homework Equations using the formula f=mg-Kv2, where g is the acceleration due to gravity, m the mass of the body, v its velocity. The terminal velocity is 120mph...
  29. B

    Velocity of falling object through fluid flowing upward

    How to calculate the velocity of a object falling due to gravity through a pipe (vertical) where the fluid is flowing in upward direction? Please ignore the frictional force & just consider F net = F (gravity) - F (drag) - F (force the fluid exerting on the object during upward flow) -...
  30. B

    Free falling object and tension on rope

    Hi I'm wondering, if I had a mass of 10kg and I dropped it 10 metres, how would I work out how much force is exerted on a rope? Thanks David.
  31. N

    Force vector on falling object to determine terminal velocity and to graph it

    Homework Statement k: constant v: velocity m: mass g: gravity Homework Equations Vt= √(2mg/CρA) F=ma The Attempt at a Solution part a. part b. I do not know if i am doing this right and i do not understand how to do part c. If you know how to do this please explain
  32. I

    Impact force from a falling object

    I used some formulas to determine the impact force of a bubble wrapped 1kg object dropped 1 meter and traveling .03m after impact. But I need some help with the next part. What if an identical bubble wrapped 1kg object is placed on top and both are dropped at the same time? Will the wrapping...
  33. S

    Speed, force, velocity, (falling object)

    Homework Statement (A) An egg (57g) is dropped from a balcony 4m high,calculate the speed with which the egg, when dropped from the first floor balcony will hit the ground. ( use Newtons laws). ( note the time taken for the egg to hit the ground is 0.1s) (B) What force from the ground will be...
  34. bleist88

    Falling object far from Earths Center of Mass Problem

    I have been thinking about how to come up with a function of time for the n-body problem. Later I found that there still is no function of time known for the n-body problem, but I am still not sure where the brick wall for everyone is because I am quite sure my understanding has hit from very...
  35. P

    How Do You Calculate Forces and Time for a Falling Object?

    Homework Statement The height of which it will be dropped 5.1816m, then the mass is 0.057kg. and the gravity is 9.8m/s^2 .What is the force downward? what's the net force and what's the up force? and what's the time to hit the ground? Homework Equations Fg=m*g The Attempt at a...
  36. T

    Free falling object with gravity

    I was trying to do this problem, but I got t negative, so I went back from the beginning and looked for my errors, but I couldn't find one. Can anyone tell me what I did wrong ? Thanks You drop a ball from a window on an upper floor of a building and it is caught by a friend on the ground when...
  37. F

    Need help calculating the odds on a falling object.

    I am working on a product development project for an aircraft application. I need a rough calculation of the odds of a particular part falling off a particular aircraft during a particular emergency of hitting a person(s) on the ground. This is to cover the contiguous United States...
  38. T

    Differential Equation: Falling Object

    Homework Statement For small, slowly falling objects, the assumption made in equation (1) (see below) is good. For larger, more rapidly falling objects, it is more accurate to assume that the magnitude of the drag force is proportional to the square of the velocity with the force...
  39. F

    Entropy change of a hot, falling object

    Homework Statement A shipyard worker drops a hot steel rivet (mass 125g, temperature 350 degrees C) into a river at temperature 5 degrees C, a distance 30m below. Stating any assumptions you make, calculate the entropy change of the universe as a result of this event. (specific heat capacity...
  40. S

    Calculating Velocity of a Falling Object with Drag Force

    First, let me preface this question that I have been out of academia for about 5 years now, and am just starting to get back into it, although it seems my Calc/Kinematics is a little rusty.b]1. Homework Statement [/b] An object of weight W is falling through a medium such that the object's drag...
  41. G

    Falling object with random pictures taken

    Suppose I drop a rock off a cliff at height h. As it falls, I snap a million photographs at random intervals. On each picture I measure the distance the rock has fallen. Ignoring air resistance: x(t) = 1/2 g t^2 v(t) = g t total flight time = T = Sqrt[ 2 h/g] My confusion is that in...
  42. P

    Reflection of a falling object on an Inclined Plane

    Homework Statement (Irodov - Problems in General Physics - 1-31) A ball starts falling with zero initial velocity on a smooth inclined plane forming an angle α with the horizontal. Having fallen the distance h, the ball rebounds elastically off the inclined plane. At what distance from the...
  43. S

    Why Do Objects P and Q Have Different Times to Reach Their Peak?

    an object, P is thrown vertically up and after 3s later another object ,Q is thrown up with the same initial speed of 20m/s and at the same position. find: a) the time, answer: [T][/P]= 3.54s, [T][/Q]= 0.54s [b]2. i use this formula v=u + at v=0 , u=20m/s a=9.8 ,t=? but my answer is...
  44. S

    How to Calculate Minimum Height for Safe Parachute Deployment

    [b]1. a free falling skydiver reaches a terminal velocity of 65m/s before opening his parachute.the parachute can provide a deceleration of 30m/[s[2]. a parchutist cannot hit the ground at a speed greater than 5m/s without risking injury. what is the minimum height at which the skydiver can open...
  45. S

    Free Falling Objects: Find Initial Velocity of Q

    [b]1. stone p is releasedfrom a cliff of height 122.5m above the ground. after falling a distance of 19.6m, another stone Q is lauched straight downward.if given that p and Q reached the ground same time, find the initial velocity of Q( answer :26.1m/s i using s=ut +1/2a[t][2] to find out the...
  46. L

    Finding Acceleration of Falling Object: Newton's 2nd Law

    A body of mass m (kg) is falling vertically under gravity g m/s2 in a medium whose resistance to the speed of the body, v m/s, is proportional to vn (n positive). If the body was released from rest and has terminal velocity, vt m/s, use Newton's 2nd law of motion to show that its...
  47. T

    Distance between falling object

    A dripping water faucet steadily releases drops 1.0 s apart. As these drops fall, will the distance between them increase, decrease, or remain the same?
  48. P

    What is the impact force of a falling object?

    Okay, I run an Emergency Services and Rescue Unit and was asked a very interesting question regarding our Roof Top Safety gear. A question I couldn't answer last night and I am desperate to find the correct answer. The question posed was as follows: How heavy would I weigh if I fell from...
  49. F

    How Fast is the Shoe Moving Before It Hits the Spring?

    Homework Statement A 0.222 kg shoe is dropped onto a vertically oriented spring with a spring constant of 101 N/m. The shoe becomes attached to the spring upon contact, and the spring is compressed 0.110 m before coming momentarily to rest. What work is performed by the weight of the shoe...
  50. I

    Differential Eq falling object + friction

    Homework Statement A point mass m falls from rest through a height h. The frictional force is given by -\gamma \dot{z} and gravity by -mg. Give the 'equation of motion' (differential equation) for the height z(t).The Attempt at a Solution \ddot{z} = -g - \frac{\gamma}{m} \dot{z} I thought...
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