Conservation of energy Definition and 1000 Threads

Homework Statement A massless spring has unstretched length Lo = 0.45 m and spring constant k = 122.3 N/m. A block of mass m = 1.87 kg is attached to the spring, and a student stretches the spring to a length of L = 1.1 m. Then the student releases the block and it shoots upward. What is...

Homework Statement A 0.150-kg frame, when suspended from a coil spring, stretches the spring 0.050m. A 0.200-kg lump of putty is dropped from rest onto the frame from a height of 30.0m. mass of frame: mf mass of putty: mp height: h Homework Equations The Attempt at a Solution...

Homework Statement A 15.0g ball is to be shot from a spring gun whose spring has a constant force of 600 N/m. The spring will be compressed 5.00 cm when in use. How fast will the ball be moving as it leaves? How high will it go if the gun is pointed vertically? Homework Equations I'm...

A five gallon bucket of water is placed five feet above the ground. The initial diameter of the pipe leading from the bucket is six inches. Energy from the falling water is captured by a water wheel. Optimally, there should be a complete transfer of energy from the water to the water wheel...

Homework Statement A circus clown of mass 52.0kg is launched vertically from a springloaded cannon with spring constant 3.5x103N/m. The clown attains a height of 4.5m above the initial position (when the spring was compressed). a) How far was the spring compressed before launch? b) what is...

Homework Statement 3. A baseball (m = 0.150 kg) is thrown with an initial speed of 30.0 m/s at an angle of 37.0 degrees from the horizontal at y = 0 m. (a) Find the initial KE of the ball. (b) Use conservation of energy (not kinematic equations) to find the maximum height reached by the ball...

Homework Statement Two blocks, A and B (mA=50 kg and mB=100 kg), are connected by a string as shown. If the blocks begin at rest, what will their speeds be after A has slid a distance d = 0.25 m? Assume the pulley and incline are frictionless. Homework Equations K= .5mv^2 P=mgh...

Homework Statement In the figure, a block of mass M slides without friction around the curved track. (a) If the block starts from rest at A, what is its speed at B? (b) What is the force of the track (the normal force) on the block at B? See Figure 1 Homework Equations Uf + Kf = Ui + Ki...

Homework Statement In the figure the second block slides horizontally without friction while the first block falls. Use the Conservation of Energy to find the speed of the blocks after they have moved 2 meters, starting from rest. The falling block has mass 3 kg, the sliding block has mass 5...

We receive energy from the sun as heat and light(radiations incld). Ok..I know that the heat we get heats up the land, water etc ... but what about the light falling on Earth .. which energy is it converted into? There is one case of it being used in photosynthesis and also converted to...

If one observer in an inertial reference measures a collision to be elastic, then all observers in an inertial reference frame will measure the collision to be elastic - can this be explained with the conservation of energy? What exactly does the conservation of energy principle say in regards...

The universe is expanding. We know this because light from distant stars is red shifted indicating that they are moving away from us. Here is the nugget that just occurred to me. Lower frequency light carries less energy so if all the light emanating from a star shifts further down in...

Homework Statement Use conservation of energy to determine the angular speed of a spool after the bucket(3.0kg) has fallen 4.00m, starting from rest. Homework Equations KE = 1/2mv^2 KEr = 1/2 * I * omega^2 PE - mgh The Attempt at a Solution i don't know how to start. I...

Conservation of Energy in a Gyroscope Thought Experiment I have posted a though experiment at the following address. I would appreciate anyone's thoughts on this. http://sibleysystems.pro/gyro/gyro.html" Thanks in advance. Jamie

Homework Statement My professor has provided me with an equation, and my task is to write a conservation of energy problem whose solution would produce said equation. Here is the equation: (1/2)(3kg)(7m/s)^2 + 0 + (0.15)(3kg)(9.8m/s^2)(2.0m) = 0 + 0 + T(2.0m) Homework Equations Work...

The cosmological constant, or dark energy if you prefer, can be thought of as energy inherent in free space. This energy density is thought to be constant, and the volume which it occupies grows as space expands. The more this happens, the more dark energy comes to dominate the universe...

Homework Statement Suppose a slide is 35.0 meters high, but is a straight slope, inclined at 45 degrees with respect to the horizontal. a) find the speed of a 60.0kg thrill seeker at the bottom of the slide, assuming no friction. b) if the thrill seeker has a speed of 20.0m/s at the...

Hello, I have a quick question regarding what goes on in air compressors. When air is compressed, I understand that we're doing a couple of things: 1. Squeezing a mass rate of air from one pressure to another - which takes work 2. Imparting heat to the gas stream - again part of doing...

In explaining why it does not make sense for two objects feeling each other's gravity to simply stay in place, the book "Simple Nature" (Ben Crowell, April 2010 edition) states that: My question is, why does one planet moving and not the other violate the conservation of energy? I could say...

A ball is rolled down a smooth ramp, that curls upwards. Where will the ball lose contact with the surface? According to the conservation of energy law, the ball is able to reach its original height, which means the ball should stop at A. However, after the ball passes point B, won't the...

Hello Guys I am a new joinee and this is my first question. I apologise if the question is little trivial. Basically, Think of the following: Scenario: There is a strong bar magnet and some magnetic metal balls lying on the floor of a room. Step 1: I lift the magnet from the floor and...

I've been thinking a lot about conservation of energy recently, and in addition to my other thread, I have another (quite different) seeming "paradox" that I can't resolve. Suppose you have a laser shooting into a Michelson interferometer with distances such that the split beam exactly...

Homework Statement A waterfall has a change in elevation of 4.4*10^2 m. When the water has fallen 12% of its way to the bottom, its speed is 93m/s. Neglecting air resistance and fluid friction, determine the speed of the water at the top of the waterfall. Homework Equations Et1=Et2...

Homework Statement A car with a mass of 1875 kg is traveling along a country road when the driver sees a deer dart out onto the road. The driver slams on the brakes and manages to stop before hitting the deer. The driver of a second car (mass of...

Doesn't the expansion of the universe defy conservation of energy, as the universe expands more dark energy is being created. That means the total energy in the universe isn't stable and is increasing.

Homework Statement A 0.500 kg mass resting on a frictionless surface is attached to a horizontal spring with a spring constant of 45 N/m. When you are not looking, your lab partner pulls the mass to oneside and then releases it. When it passes the equilibrium position, its speed is 3.375...

Homework Statement (Figure attached to post) A box of mass m is pressed against (but is not attached to) an ideal spring of force constant k, compressing the spring a distance x. After it is released, the box slides up a frictionless incline as shown in Fig. 7.5 and eventually stops. If we...

Homework Statement A hemispherical Bowl of mass M rests on a table. The inside surface of the bown is frictionless, while the coefficient of friction between the bottom of the bowl and the table is u = 1. A particle of mass m is released from rest at the top of the bowl and slides down...

When a rubber balloon of spherical shape with un-stretched radius 0 r is inflated to a sphere of radius r ( ≥ r0 ), the balloon surface contains extra elastic energy due to the stretching. In a simplistic theory, the elastic energy at constant temperature T can be expressed by U= 4\Pi...

Since we all know that energy is conserved, it is converted from one form to another, I want to ask you what happens to the energy when a compressed spring, in a vacuum is released? Where does the energy go, does it simply become heat energy in the spring, or is it transferred another way?

Hello. Can someone help me with this problem please? An inclined plane of angle theta = 20.0 has a spring of force constant k=500 N/M fastened securely at the bottom so that the spring is parallel to the surface as shown in figure P7.63. A block of mass m = 2.50 kg is placed on the plane at a...

Homework Statement An 8.70kg block slides with an initial speed of 1.66m/s up a ramp inclined at an angle of 27.4 degrees to the horizontal. The coefficient of kinetic friction between the block and the ramp is 0.3. Use energy conservation to find the distance the block slides before coming...

According to quantum field theory there is an intrinsic energy of the vacuum or zero point energy (which is being related to cosmological constant by some cosmologists, i.e.:http://philsci-archive.pitt.edu/archive/00000398/00/cosconstant.pdf ), so if space stretches with expansion, is the...

If an object absorbs a graviton, can it emit the same graviton? I would think that the gravitational energy would have to be transmitted to the object and if the object emitted the graviton again, it would lose the effect the graviton had on it. But I read somewhere that gravitons are not...

This is a question concerning the wave nature of light and the conservation of energy. Consider a prism that combines two sources of monochromatic, coherent (laser) light into one beam. The sources are adjusted so that the laser beams combine in phase resulting in constructive interference...

This is something that I have wondered about for a while now which is related to how tidal power stations work and the law of conservation of energy. Scenario: As far as I am aware the tidal variations all around the world are primarily caused by the gravitational force of the moon on the...

Homework Statement There is a tower and a heavy box in it, which weighs 20.000 kg. This box falls down from 70m and after falling 40m(free fall), she is slowed down by magnets on the surface of the box, which interact after falling 40m with copper plates on the tower, which weigh 2.000kg. Then...

I have seen this topic discussed a bit on the web, but I don't see any clear answers. I takes a lot of energy to make the moon go in a curve, if you had to do it with rockets you would need a lot of fuel. Therefore it takes a lot of energy to make the moon go round the Earth for 4 billion...

Hello everyone, first time posting in here. Heres a question, in Lenz's Law, it states that the current produced will be opposite of the motion that created it. This is done by the repulsion or attraction force created by the solenoid to counter the motion of the magnet. Now, without the work...

Homework Statement An elastic string of natural length 3.0m can be stretched to a length 4.0m by a weight of mass 10.0kg. Its two extremities are fixed to two points A, B in the same horizontal line at a distance of 4.0m apart, and a mass of 15.0kg is attached to the mid-point. If this mass is...

Homework Statement 1. A blue puck with a mass of 0.0400 kg, sliding with a velocity of magnitude 0.200 ms-1 on a frictionless horizontal table, makes a perfectly elastic, head-on collision with a red puck with mass, m, initially at rest. After the collision, the velocity of the blue puck is...

Homework Statement 2 masses mass m connected by a light string length l. One moves on a smooth horizontal table in which there is a small hole. The string passes through the hole so that the second mass hangs vertically below. Asked to use conservation of energy and angular momentum to show...

Homework Statement An interaction occurs when two strong magnets are held stationary with the north pole of one pushed against the north pole of the other. On letting go, the magnets spring apart. It is apparent that the kinetic energy of the magnets has increased. Explain how the law of...

Homework Statement A bowling ball is rolling without slipping up an inclined plane. As it passes a point O it has a speed of 2.00 m/s up the plane. It reaches a vertical height h above O before momentarily stopping and rolling back down. Determine the value of h. The moment of inertia of a...

1. Find the equation for conservation of energy in system. System consists of three springs A,B and C with stiffness k, 2k and 0.5k respectively and natural lengths l, 0.5l and 2l respectively. Homework Equations Equation for conservation of energy E=K+U_{spring}+U_{gravity}...

Length contraction is one of the main aspects of relativity. However, I have a question: When something undergoes length contraction, does it become more dense or, is the decrease in length radiated in some way? Thank you, Jake

Homework Statement delta E = 0 = delta K + delta U delta U = -delta K mg(h - h_0) = m/2 (v_0^2 - v^2) or in its common form mgh - mgh_0 = (m v_0^2)/2 -(m v^2)/2 mgh + (m v^2)/2 = (m v_0^2)/2 + mgh_0 which is how msot people perfer to memorize very simple intro to physics...

Homework Statement Your favourite physics teacher who is late for class attempts to swing from the roof of a 24m long rope as shown in the picture. The teacher starts from rest (Ek=0) with the rope horizontal, but the rope will break if the tension force in it is twice the weight of the...

Homework Statement Ok so I am solving a SR problem...using conservation of energy and momentum I've got to: Gamma a + 2 Gamma b = 5 And Gamma a * Va = -2 Gamma b * Vb where gamma is the usual gamma in SR! a and b are labels for 2 particles.. Just need a quick way to solve to find...

Hey if anyone can help me figure out a practical application that applies the principles of energy and momentum it would be greatly appreciated. It also has to have some environmental or impact on society.