Falling Definition and 1000 Threads

Homework Statement A ball falls on the surface from 10m height and rebounds to 2.5m.If duration of contact with floor is 0.01 sec,then average acceleration during contact is- g = 10m/s^2 Homework Equations \alpha = \frac{v_2 + v_1}{t} The Attempt at a Solution Now here v_{1}...

Homework Statement A stone is thrown off a high cliff with speed 30m/s at an angle 0 degrees. At what angle is the stone's velocity 2 seconds after it's thrown. (measired with respect to the horizontal x direction(angle will be negative)) Homework Equations angle = tan(Vy/Vx)...

At an altitude of 315 m above a lake, a hot-air balloon pilot drops a 2.50 kg sandbag. If the bag comes to a stop 4.50 m below the surface of the lake, what force was applied by the water on it? I was thinking v= 2.50kg x 9.81km/h= 24.525m/s i can't remember how to get the force

Homework Statement m1 and m2 only interact gravitationally. They are initially at rest and a distance L apart. They where then released. Where and when will they collide? Homework Equations F_g=G\frac{m_1m_2}{x^2} The Attempt at a Solution For the where part, my argument is that...

Homework Statement the question goes like this a man of mass 70kg falls onto a rescue cushion from a height of 7 m he comes to rest 0.2s after he reaches the cushion the cushion is 2m high when inflated a)find the impact force acting on him (take the weight of the man into...

Question: A stone is falling from the top of a buliding with 32m/s. Air resistance is so small that it can be neglected. the weight of the stone is 24N. Calculate the time in second which the stone takes to reache the ground.

Question: A stone is falling from the top of a buliding with 32m/s. Air resistance is so small that it can be neglected. the weight of the stone is 24N. Calculate the time in second which the stone takes to reache the ground.

Does a free falling ball drops on Earth violate this theory? If we consider the ball and Earth in an isolated system then the ball should continue to drop over time. If the impulse given is extremely negligible that it doesn't cause any significant change in the path of earth, then the...

Homework Statement Gravity on a falling object causes the object to descend a distance of d=4.9t^2, where d is the distance in meters and t is the time in seconds. A bowling bll is dropped from the top of the Eiffel Tower in Paris, France, which is 324 meters in height. If you neglect any...

At t = 0 a rubber ball of mass m is dropped from a height of 10 m. (i) When does it reach the ground? How fast is it moving when it hits the ground? Each time it bounces, the ball looses 20% of its energy. (ii) Calculate the height it reaches on the 1st bounce, and the time at which it hits...

Homework Statement Two small balls with masses 3M and M hang on elastic massless rubber bands (with the M ball attached to and suspended beneath the 3M ball with one rubber band; the 3M ball is suspended from the ceiling by a separate rubber band). When the band between the balls is cut...

Homework Statement A conducting ring with radius a and mass m is placed in a magnetic field at a height H above the origin of the reference frame. The plane of the ring is parallel to the ground, that is, the normal is directed along the z-axis. The electrical resistance per unit length of...

A flowerpot is knocked off a balcony 20.0m above the sidewalk and falls toward an unsuspecting 1.75-m tall man who is standing below. How close to the sidewalk can the flowerpot fall before it is too lat for a warning shouted from the balcony to reach the man in time? Assume the man below...

Wald says (paraphrased) "Let us attempt to destroy a black hole and create a naked singularity. Kerr-Newman black holes satisfy the relation M^2\ge Q^2 + (J/M)^2, where M,Q,J are the mass, charge and angular momentum of the black hole (and G and c are taken to be 1). Let us start with a...

If a ball is thrown upwards, another straight out, and another downwards, which will reach the ground with the highest velocity? After thinking about this for a while my conclusion is that they all will have the same velocity since they all have the same initial gravitational potential energy...

Homework Statement A biologist working 80 meters high in the Amazon tree canopy drops her pliers used for crimping bands on animal legs. 1) Assuming the pliers hit nothing on the way to the ground, how fast will the pliers be moving when they reach the ground? 2) When the pliers...

Homework Statement A 4.7 kg block is placed on an incline with a 14° angle. Ignoring friction, what is the acceleration of the block? If the coefficient of kinetic friction is 0.25 (and has overcome static friction) what is the acceleration of the block? If the incline is 4.6m long, what is the...

Homework Statement While on planet X, an object is thrown vertically upward with an initial velocity of 5m/s. If this object returns to the point of release in 3s, what is the acceleration of a free falling object on this planet? Homework Equations a=vf-vi/t The Attempt at a...

A mass M is released from rest on a smooth plane inclined to the horizontal at 14 degrees. Find the time taken for the mass to travel 1m down the incline and the velocit attained at the end of that time. I had no trouble with the first part - measuring the velocity and time for the part where...

Homework Statement Hi all - apologies now if there is a thread on this very problem, but I have searched the web and still can't seem to find something to help me. Okay the problem: I am trying to solve a problem that has been bugging me and I think I am missing something I have ball...

Homework Statement A 700 g block is released from rest at height h0 above a vertical spring with spring constant k = 445 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 20.5 cm. (a) How much work is done by the block on the...

Homework Statement A 7.0m -tall electrical pole with mass 260 kg has a 42 kg electrical transformer attached to its very top. The pole is hit by lightning at its base, nearly severing the pole from its base. The pole begins to fall, rotating about the part still connected to the base...

Homework Statement Hi all. I've got a vertical rod on a surface with a fixed and frictionless pivot at bottom end. The rod of length L is released and begins to fall. The forces acting on the CM of the rod should be: - weight force: mg - centripetal (radial) force...

Homework Statement A limp rope with a mass of 2.4 kg and a length of 2.1 m is hung, initially at rest, on a frictionless peg that has a negligible radius (see figure). The short end has length y1 = 0.84 m. What is the vertical velocity of the rope just as the end slides off the peg...

Homework Statement A 69 kilogram person falls from a 35 meter tower head first to the ground Homework Equations What is the maximum velicoity he reaches before impact? The Attempt at a Solution

Homework Statement A metal bar of length 1.3 m and mass 0.04 kg slides with negligible friction but with good electrical contact down between two vertical metal posts. After speeding up initially, the bar falls at a constant speed (zero acceleration). The falling bar and the vertical metal...

Homework Statement mass of steel ball = 40g = .04 kg h1 = 2.00 m h2 = 1.60 m A steel ball is dropped from height of 2.00 m onto horizontal steel slab, rebounds to height of 1.60m. Calculate impulse of ball during impact. Homework Equations impulse J = F*dt J = P2 - P1 I tried...

I have been out of school for a few years so my physics is rusty. I need help figuring something out for my job. I need to know how high I must drop an object so that it hits the ground with an impact of 1000g's. The object is a cylindar and weighs 2lbs. I have been confusing myself. I...

Can this be explained in terms of inelastic collisions? This is what I think: The collision is perfectly inelastic because the person and the net move together with the same velocity. This means that the initial kinetic energy of the system (and therefore the kinetic energy of the person) is...

A toy car runs off the edge of a table that is 1.325 m high. The car lands 0.425 m from the base of the table. How long did it take to hit the ground? How fast was the car going? My tutor even had trouble with this, without a speed this is no solvable, at least to me. Suggestions on...

Homework Statement http://img202.imageshack.us/img202/3459/phys.png Homework Equations \DeltaY=VoYt+1/2gt2 The Attempt at a Solution Rearranging the equation (using \DeltaY=h), I get \sqrt{}2h/g which, from what I understand, means it takes \sqrt{}2h/g seconds for the monkey to...

Homework Statement If a fish is attached to a vertical spring and slowly lowered to its equilibrium position, it is found to stretch the spring by an amount d. If the same fish is attached to the end of the unstretched spring and then allowed to fall from rest, through what maximum distance...

Homework Statement From the top of a tall building, a gun is fired. The bullet leaves the gun at a speed of 340 m/s, parallel to the ground. As the drawing shows, the bullet puts a hole in a window of another building and hits the wall that faces the window. (y = 0.48 m, and x = 6.0 m.) Using...

Homework Statement Stephanie hits a volleyball from a height of 0.8m and gives it an initial velocity of 7.5m/s straight up.? a. how high will the volleyball go? b. how long will it take the ball to reach its maximum height? (hint:@ max height, v= 0m/s) Homework Equations im not...

Homework Statement A parachuter of mass 75 kg falls towards the Earth at a speed of 25 ms-1. What is the resultant force acting on the person? a. 750 N b. 450 N c. 1,350 N d. No net force e. 1,500 N Homework Equations F = ma The Attempt at a Solution I think the answer is...

Homework Statement The question I'm working on says "A special, frictionless, thin meter stick is initially standing vertically on the floor. If the meter stick falls over, with what angular velocity will it hit the floor?" Homework Equations v_rot=rw, I=1/12mL^2, KE=1/2Iw^2 The...

So i was thinking, if you drop a ball that has a bouncy property to it, it will travel half as high after the bounce, then in theory it will bounce half as high, and half, and half, and half but never reaches zero this is not true in reality though, because there of a loss of energy due to...

Homework Statement A baseball is seen to pass upward by a window 28 m above the street with a vertical speed of 8 m/s. The ball was thrown from the street. (a) What was its initial speed? (b) What altitude does it reach? (c) How long after it was thrown did it pass the window? (d)...

I'm given the initial conditions vnot=0m/s, hnot=3000m, and tnot=0s After 35 seconds of freefall, the chute opens. I am to write a piece-wise define diff equation for the rate of change of velocity, with the two pieces t<35 and t >_35. I am not given a mass. Now, I understand how to...

Homework Statement A flowerpot falls past two meter tall window in ¼ of a second. From what height did the flowerpot fall? Homework Equations To calculate the velocity of the pot while this is passing the window: v = d/t To calculate the height: v^2= v0^2 = 2gh → h= (v^2 - v0^2) / 2g...

Hello, I have got an question. How can I calculate the velocity of an object which I'll drop from a height of 1 meters with a starting velocity of 0 m/s? I did some research myself and found out that I can calculate this with using the following formula: St = 0.5 * 9.81 * t^2 St =...

A freely falling object requires 1.10 s to travel the last 20.0 m before it hits the ground. From what height above the ground did it fall? (Ans. in m.) I am completely lost on modeling this problem. Please help me figure it out.

Homework Statement In the Niagara Falls hydroelectric generating plant, the energy of falling water is converted into electricity. The height of the falls is about 50 meters. Assuming that the energy conversion is highly efficient, approximately how much energy is obtained from one kilogram...

Homework Statement the effect of air resistance is to slow down a moving object. It can be shown that height of a falling object is given by the following Homework Equations y=y0-[t+(e^-bt - 1)/b]g/b a. show that for short times this reduces to the expected expression y=y0-1/2gt^2...

Homework Statement A crane is in the process of lifting a pallet of bricks to the upper floor of a building. Suddenly a brick slides and falls off the rising pallet. You clock the time it takes for the brick to hit the ground at 2.5 seconds. The crane has height marking and you see that...

Homework Statement A wrecking ball is hanging at rest from a crane when suddenly the cable breaks. The time it takes for the ball to fall halfway to the ground is 1.31sex. Find the time it takes for the ball to fall from rest all the way to the ground. I think the formula to use is...

The velocity of a diver just before hitting the water is -10.2m/s, where the minus sign indicated that her motion is directly downward. What is her displacement during the last 1.10sec of the dive? I tried to use dthe x=1/2(Vinitial + Vfinal)t=40.8 but it's wrong, what am i doing wrong??

If you stand motionless under an umbrella in a rainstorm where the drops fall vertically, you remain relatively dry. However, if you start running, the rain begins to hit your legs even if they remain under the umbrella. Why?Now I know the answer, it's because when you run horizontally, your...

Can somebody please show me how to solve this problem? A flowerpot falls off a windowsill and falls past the window below. You may ignore air resistance. It takes the pot 0.420 s to pass this window, which is 1.90 m high. How far is the top of the window below the windowsill from which the...

While I was looking up about free falling chain problem(the question about a chain falling on to a table), I wondered how it would be if the chain is knotted. What I'm thinking is that if the chain has a knot, would it make much difference? Two questions; 1) Once the knot hits the table...