Free fall Definition and 486 Threads

Homework Statement When the ball dropped from a height of 2.5 m on the floor, it bounces back to 1.4 m in height. Air resistance is taken into account. g= 9.81 m/s2 Homework Equations a) the speed at which the ball hits the floor? b) How much of the energy consumed in collision with a...

Help! Free fall, looking for time of motion off of a bridge. Homework Statement A person standing on a bridge throws a ball upward with an initial velocity of 23 m/s straight upwards so if it comes back down it will just pass the edge of the bridge and keep going down. a) where will the ball...

Homework Statement On September 8, 2004, the Genesis spacecraft crashed in the Utah desert because its parachute did not open. The 210-kg capsule hit the ground at 311 km/h and penetrated the soil to a depth of 81.0cm . Assuming it to be constant, what was its acceleration (in m/s2 )...

1. Calculate the percent difference of freefall acceleration for the light and heavier picket fence Lighter Picket Fence - Mass 95.84 g | Acceleration 6.4141 m/s2 Heavier Picket Fence - Mass 128.16 g | 8.995 m/s2 2. Compare each of the values from the graphs to the accepted value of free...

While riding on an elevator descending with a constant speed of 3.0 m/s, you accidentally drop a book from under your arm. How long does it take for the book to reach the elevator floor, 1.2 m below your arm? What is the book’s speed when it hits the elevator floor?My question is why is 3.0 m/s...

Homework Statement A crate is hanging from a cable as shown in the diagram. A monkey that is inside the crate, sits on a ledge that is 1.225m above the bottom of the crate. The monkey steps off the ledge and when he hits the bottom of the ledge, it takes .125 s to stop. The tension in the...

Homework Statement What are the applications of free fall in our daily life? Homework Equations How is it applied?The Attempt at a Solution One example is sky diving,I need to know more. A sky diver must have knowledge on the concept of free fall like what position he/she should be into...

Homework Statement Design a simple Op Amp circuit to find the position as a function of time of a falling body Homework Equations y=y_0+1/2gt^2 Assume y_0 = 0 at t=0 The Attempt at a Solution I used an integrator Op Amp with a triangle wave input. I chose the values of the...

Hello, I am new to this site. I am currently active duty military (navy) and I am trying to teach myself physics because when I get the time, I would like to take some college physics classes. I downloaded a few physics books online and I am trying to page through them. I am having some...

Homework Statement . A ball is thrown straight up at t=0. It is found to be falling with a speed of 8 m/s at t= 6 sec. Find the displacement of the ball.Homework Equations The Attempt at a Solution v=v0-gt 8=v0-60 v0=68 deltax =v0t - .5gt2 delta x = (68*6)- 5*36=228 but it says the answer is...

Homework Statement Jane is riding in a hot air balloon that is rising vertically at a constant speed of 3m/s over a lake. She reaches out and drops a rock from the balloon when the distance from the rock to the water is 50m. Use g=10m/s2, and let the up direction be positive. How long...

Homework Statement For a brief moment, the human body can withstand accelerations of up to 75g. If a sky diver is unlucky enough to have a parachute fail, and hits the ground with a terminal velocity of 50 m/s, what is the minimum distance over which he can come to a rest (assuming constant...

first of all I have a case that is screwed in another case ,I like to know a basic way to calculate the impact force in the screws ,the are 16 screws, I try using the basic impact force formula and the conservation of energy in the free fall,but I am having problems since I don't have the D...

D=Drag Coefficient p=Density of air A=Cross sectional area v=velocity a=acceleration F= force F air=(DpAv^2)/2 F net=mg-F air ma=mg-F Air a=g-(DpAv^2)/2m k=DpA/2m so a=g-kv2 dv/dt=g-kv2 dt=dv/g-kv2 using the online integrator from wolfram we got...

Homework Statement Does the acceleration of free fall take the effect of air resistance into account or is it equal to the acceleration of free fall on Earth if the Earth was in a vacuum? Thanks Homework Equations The Attempt at a Solution

If air would be compressed to have equal pressure to that of water would objects which are buoyant in water be buoyant in such compressed air too or would they still fall down due to Earth gravity? Or asking differently, what would have to be the pressure of air (lower, equal or higher than...

Free fall, problem, please help Homework Statement A hoist is lifting a naturalist to the top of a cliff at 2.03 m/s vertically. The naturalist suddenly realizes she has left her pet rock behind. A friend picks it up and tosses it straight upward. If the naturalist is 2.50 m above her friend...

Homework Statement A rock is dropped from a sea cliff, and the sound of it striking the ocean is heard 3.7s later. If the speed of sound is 340m.s how high is cliff? Homework Equations Ttotal=trock+tsound distance=Vsound*tsound ts=340m/s-trock x=x+vt+.5at^2 quadratic equation...

Homework Statement Hello. Can someone please give me a clue as to what I'm doing wrong and why I'm doing it wrong? Thank you. The problem is: A steel ball is dropped from a building's roof and passes a window, taking 0.13 s to fall from the top to the bottom of the window, a distance of...

Homework Statement As a runaway scientific balloon ascends at 19.6 m/s, one of its instrument packages breaks free of a harness and free-falls. The figure below gives the vertical velocity of the package versus time, from before it breaks free to when it reaches the ground. (a) What...

Homework Statement Two balls are are released from a table top of height H = 3m at the same time. The green ball is given an initial velocity v0 = 6 m/s in the downward direction, while the red ball is given an initial velocity v0 = 6 m/s in the upward direction. How long does it take for the...

Homework Statement A ball is thrown upward in such a way that its speed is 32.3 m/s when it is at half its maximum height. Find (a) its maximum height, (b) its velocity 2.0 s after it's thrown, (c) its height 2.0 s after it's thrown, and (d) its acceleration at its maximum height...

Homework Statement a hot air balloon is ascending at the rate of 10 m/s and is 61 m above the ground when a package is dropped over the side. with what speed does it hit the ground Homework Equations y(final) - y(initial)= vt + .5at^2 v(final)=v(initial) + at a= -g = 9.8 m/s...

Homework Statement A bolt comes loose from underneath an elevator that is moving upward at a constant speed of 6.0 m/s. The bolt reaches the bottom of the elevator shaft in 3.0 s. a.) How high above the bottom of the shaft was the elevator when the bolt came loose? b.) What is the...

Another free fall topic :) Here I don't really know where to start Homework Statement A body in free fall covers 64% of the total distance fallen in the last second. From what height did it fall? Homework Equations y= y1 + y2, where y1=0,36y and y2=0,64y y=.5at², where a=g=9.8...

1. A ball is thrown vertically upward with an initial speed of 10m/s from thetop of a building, at a height of 25m from the ground. Assume free fall conditions. a. To what maximum height above the ground does the ball rise? b. With what velocity does the ball strike the ground? c. How long...

I read about this stuff a few years ago, and it seems that nobody gives too much attention to it. Its about an experiment with "cold" neutrons in free fall, and here is the original publication (2004) found on Institut Laue-Langevin's website...

Homework Statement A stone is thrown vertically into the air from a tower 110 ft. high at the same time that a second stone is thrown upward from the ground. The initial velocity of the first stone is 60 ft/s and that of the second stone 85 ft/s. When and where will the stones be at the same...

A 10 kg mass is in free fall with no air resistance. In order to slow the mass at a rate equal to the magnitude of g, an upward force must be applied with magnitude: F=ma F=(10kg)(9.81m/s2) = approximately 100N So in order to slow the mass at a rate equal to g it should be a...

Can you help me with this please, an approach on how to proced would be great. Homework Statement From top of a tower two bodies are dropped with the same velocity Vo and same inclinations \alpha1 \alpha2. both bodies fall in the same point of the ground. Calculate the hight of the tower...

I have this question on my Circular motion assignment, but its somehow connected to free fall. I'm unable to picturize the situation mentioned in question... A 3.35 kg block is attached to a string that is wrapped around a 1.22 kg, 5.03 cm diameter hollow cylinder that is free to rotate on an...

Homework Statement A rock climber stands on top of a 50-m-high cliff overhanging a pool of water. He throws two stones vertically downward 1.0 s apart and observes they cause a single splash. The initial speed of the first stone was 2.0 m/s. a) How long after the release of the first stone...

1. A rock is dropped from rest from a height above a strange planet, and a strobe-light photograph is taken. The image is damaged in transmission to Earth so that an unknown part of the top of the picture is lost. However, five successive images of the falling rock can be seen. The spacing...

I've been trying to derive the full solution to the problem of free fall when the distances considered are large (and hence, the acceleration is no constant, but a function of height). This isn't homework, I was just curious. The problem is innocently simple, but yields a differential equation...

Homework Statement To find the height of an overhead power line, you throw a ball straight upward. The ball passes the line on the way up after 0.85 s, and passes it again on the way down 1.2 s after it was tossed. (a) What is the height of the power line? (b) What is the initial speed...

Homework Statement While riding on an elevator descending with a constant speed of 3.3 m/s, you accidentally drop a book from under your arm. (a) How long does it take for the book to reach the elevator floor, 1.0 m below your arm? (b) What is the book's speed relative to you when it...

Homework Statement I am having a heck of a time trying to solve these problems. Please help if you can. A hot air balloon has just lifted off and is rising at the constant rate of 2.4 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up...

Homework Statement An object is in free fall at the surface of the Earth. In a certain 1.0 second time interval, the average velocity of the object is measured to be 2.0 m/s downward. What was the velocity of the object at the beginning of the 1.0 second interval? Homework Equations...

Homework Statement Two 54kg blocks are held 30cm above a table. As shown in the figure, one of them is just touching a 30cm long spring. The blocks are released at the same time. The block on the left hits the table at exactly the same instant as the block on the right first comes to an...

Homework Statement A tennis ball is hit down at an angle of 30° below the horizontal from a height of 2 m. It is initially traveling at 5.0 m s−1. What is the velocity of the ball when it hits the ground if we can neglect air resistance?Homework Equations The Attempt at a Solution ok so I...

Homework Statement An astronaut on a strange planet finds that she can jump a maximum horizontal distance of 15 m if her initial speed is 3 m/s. What is the free fall acceleration on the planet? Homework Equations R=Vi^2sin2α/g The Attempt at a Solution 15=9sin2α/g g=9sin2α/15

Homework Statement Describe the motion of a light bulb falling from the ceiling of a train with a constant acceleration. The train's motion is horizontal with respect to the ground. Describe the motion of the light bulb if you are at rest on the rails. If you are at rest on the train. If...

Hello, first post. I hope that someone can help me with this. I will roughly summarize the problem, and what I've done thus far. Homework Statement A lady was in an elevator that free-fell 6 feet and abruptly came to a halt. We had to determine a reasonable best case and a reasonable worst...

Suppose a 136 kg manhole cover is launched 50 feet in the air. What is the speed of the manhole cover when it hits the ground on its descent, in m/s and mph? I converted 50 feet to 15.24 meters, but I do not know what equation to use here. I understand that acceleration due to gravity is...

Figure 2-42 shows a simple device for measuring your reaction time. It consists of a cardboard strip marked with a scale and two large dots. A friend holds the strip vertically, with thumb and forefinger at the dot on the right in Figure 2-42. You then position your thumb and forefinger at the...

Free fall problem, Help!? Homework Statement Hi, I am having trouble figuring out this problem: A ball is thrown directly upward with an initial velocity of 10 m/s. If the ball starts at an initial height of 2.3 m, how long is the ball in the air? Ignore air drag. Homework Equations...

(I apologize in advance if this should have been merged with my other topic. Homework Statement A 1000kg weather rocket is launched straight up. The rocket motor provides a constant acceleration for 16s, then the motor stops. The rocket altitude 20s after launch is 5100m. You can ignore any...

Homework Statement After falling from rest at a height of 29.8 m, a 0.422 kg ball rebounds upward, reaching a height of 21.7 m. If the contact between ball and ground lasted 1.83 ms, what average force was exerted on the ball? Homework Equations Change in momentum (p) = Fnet* Change in...

Homework Statement You drop a stone into a deep well and hear it hit the bottom 4.00 s later. This is the time it takes for the stone to fall to the bottom of the well, plus the time it takes for the sound of the stone hitting the bottom to reach you. Sound travels about 343 m/s in air. How...

"Accelerated charges radiate." That much-repeated phrase is the extent of my familiarity with radiating charges, though I am trying to bring myself up to speed on the Abraham-Lorentz-Dirac force. Well, in relativity theory gravity is locally equivalent to an accelerating frame. so if we...