Platform Definition and 142 Threads

Homework Statement Have platform A that is being spun by a centrifuge with a radius R1 and centripetal velocity of w1. On top of platform A is a Lazy Susan (Platform B) that spins about a radius R2 with a centripetal velocity of w2. There are accelerometers placed on the the purple platform...

Hi all, Consider the following SR scenario: In a frame S: A ball is resting on a platform that is parallel to the x axis. The platform is moving downward at a constant velocity parallel to the y axis. We assume a constant gravitational field whose lines of force are parallel to the y axis. In...

Hi, I am trying to design a lifting platform for light duty loads (3d printing build platform) that only uses rotation for its actuation. I have a design that uses a mechanism similar to the slider crank and I want to maximize the total height the platform can travel. This is a sketch of my...

Hi, I am designing a vibrating platform that will move strictly up and down (total displacement of 1 inch). The load on the platform will vary between 0 and 160kg. The mechanical assembly/mechanism (which is underneath the platform) is motor>belt>flywheel>crank attached to a 1 inch shaft long...

Hey folks, I'm building this steel platform to support a furnace, the furnace will weigh about 350kg and cover approximately the area shown below: The platform itself is mild steel sheet, 100cm x 100cm x 4mm thick. Each castor is rated for 300kg each. The problem I'm having is that even with...

Hi all, I'm new here on Physics Forums and can't wait to delve into some juicy topics! I have a very practical problem that I need help with. I am doing a home project where I want to move a platform on wheels (loaded to a maximum of 70kg) in a 1.5m long straight line across the floor at a...

Suppose I am stationary in space (no velocity). My body is straight. There is a stationary ball right beside me (also no velocity). Then an accelerating platform hit my feet and the ball from under. Now the ball and I are in contact with the platform constantly and accelerate at the same rate as...

A girl stands on a platform and pulley system. The masses of the platform, girl and pulley are M, m and u respectively. The rope is mass-less. Let the girl pull up on the rope so that she accelerates a upwards. What is the tension of the rope? What is the normal force between the person and the...

Homework Statement Two construction workers each of mass m raise themselves on a hanging platform using pulleys as shown above. If the platform has a mass of 1.2⋅m, the initial distance between the pulleys and the platform is d, and the workers each pull with a force f on the ropes, what is...

Hi, this is my diesel-electric conversion for what was a battery only powered platform truck. Its got a 30hp diesel engine, a 6 Kw DC generator, and another 6 Kw AC generator. One thing to point out is that I'm running it only with the generators, no batteries. Here's some pics of it: Diesel...

Homework Statement Starting from rest, a 65 kg athlete jumps down onto the force platform from a height of .6 m. While she is in contact with the platform during time interval 0s-.8s, the she exerts on it is described by the function F=9200t-11500t^2 where F is in N and t is in s. a) What...

Homework Statement A physics student is sitting on a rotating platform. He is holding a heavy weight in each of his outstretched hands. At request of his physics instructor(!) he carries out various manoeuvres to try to change his angular velocity. Which of the following scenarios are described...

1. A platform is executing simple harmonic motion in a vertical direction with an amplitude of 5 cm and a frequency of 10/pi vibrations per second. a block is placed on the platform at the lowest point of its path. a) at what point will the block leave the platform? b)how far will the block...

I'm building a small platform that is made of wood. It measures 40" x 12". It's also 1" thick. I have 4 hollow aluminum pillars that will support it. They are each 8" high and 2" in diameter. What is the optimal position for each pillar to be fixed relative to the edge of the platform? I would...

I'm building a 6'x12' steel platform that will be 3' elevated from the ground. How can I determine what load bearing weight will be if I use 2" Square Tubing, 1/4" wall thickness and then use 1/4" angle iron for the platform structure? I was going to use 2" Sq tube, 3/8" thick, but most local...

Homework Statement A hinged platform flagpole weighing 500 Newtons is supported in the horizontal position by a cable as shown in figure 4.35. Find the tension in the cable and the horizontal and vertical forces at the hinge. Angle ø = 30°Homework Equations ∑F=0 ∑T=0 T= F* the lever armThe...

Here is another train and platform example, offered to examine ghwellsjr's view equating what you see with what is real. Assumptions: Train has proper length 100. Platform has proper length 60. Train and platform are in relative inertial motion at 0.8c. There are two observers on the...

Hi all, I'm sure that things similar to this have been covered before. Also, I'm sure that a Minkowski diagram would probably clear things up no end but, anyway, please bear with me. Let's assume that we have our familiar railway carriage packed with observers who are satisfied that they...

Homework Statement A 4.50x10^5kg space platform is speeding up from 2.300x10^3m/s to 2.600x10^3mls because a rocket fires with a thrust of 138kN in space. How long must the rock fire to do this? Homework Equations F=ma F=ma+mg The Attempt at a Solution I have tried to find...

Homework Statement Two people are standing on a 2.0-m-long platform, one at each end. The platform floats parallel to the ground on a cushion of air. One person throws a 6.0-kg ball to the other, who catches it. The ball travels horizontally. Excluding the ball, the total mass of the platform...

Suppose a cylinder is resting on a horizontal platform on plane x-y with its axis parallel to the y axis, and the platform accelerates in the x direction. Assume that the axis remains parallel to the y-axis and the surface is rough. What is the motion (acceleration:linear as well as rotational)...

Homework Statement A car is driven on a large revolving platform which rotates with constant angular velocity ##\omega##. At t=0, a driver leaves the origin and follows a line painted radially outward on the platform with constant speed ##v_0##. The total weight of car is W and the coefficient...

Homework Statement Two construction workers each of mass m raise themselves on a hanging platform using pulleys as shown above. If the platform has a mass of 0.5m, the initial distance between the pulleys and the platform is d, and the workers each pull with a force f on the ropes, what is...

I am making a flat platform with 4 leveling feet that can hold a heavy duty blower which is around 200 lbs. The platform is 21.5" x 22.5" as shown in this image (let me know if there are better designs): I thought about using 0.5" steel plate but with these dimensions, it will cost me $200+...

I need to build a platform (10 in off the ground) that can hold a fan, air damper and silencer which is in total around 300 lbs of weight. I was looking at these leveling mounts that I could use for the table feet: I noticed that there is one that says 300 lbs capacity per mount and...

Looking for a bit of help on finding some advantages and disadvantages of using this proposed stewart platform (cable) system (James Albus invention) on a tower crane. How would it improve load control? Would it genuinely stop the load from swaying? Would it allow for more accurate positioning...

Homework Statement A aerialist on a high platform holds on to a trapeze attached to a support by a 8.2-m cord. Just before he jumps off the platform, the cord makes an angle α of 39.8deg with the vertical. He jumps, swings down, then back up, releasing the trapeze at the instant it is 0.64 m...

Homework Statement A block is on the platform of an accelerating truck. The coefficient of static friction between the block and the platform is 0,25. What is the minimum time in which the truck can accelerate so that the block won't slide. During the acceleration the truck travels 75 meters...

Hi so I am trying to build a rotating platform for a system consisting of two 12in. subs approximately 60 pounds, I would like it to rotate 180 degrees and then back with the flip of a switch if possible. I have absolutely no experience in this what-so-ever and all of the auto places want to...

Homework Statement A train is passing a platform at 0.75c, and an observer, stationary and at the middle of the platform, sees two bolts of lightning simultaneously hit the front and back of the train when the train's middle was adjacent to the middle of the platform. A passenger on the train...

Then read the Texas Republican Party 2012 Platform report. A few examples: "We recommend that local school boards and classroom teachers be given moreauthority to deal with disciplinary problems. Corporal punishment is effective and legal in Texas." and "We oppose the teaching of Higher Order...

I had my physics midterm today and I totally blanked out. I want to know how to solve it for next time. So In the picture, there are two springs connected to the mass on a platform. a) if the platform is at rest, find the angular frequency the expression for angular frequency is...

Hi all! There are actual task to specialists. I have a problem. There is a platform. It made ​​of aluminum 300x400x10 mm and must moving strictly along one axis (for example X axle). The Y and Z axis of this platform should be very tightly held. We can not allow fluctuations of Y and Z...

Homework Statement A person is on a horizontal rotating platform at a distance of 4.3 m from its centre. This preson experiences a centripetal acceleration of 56m/s^2. What is the centripetal acceleration is experienced by another person who is at a distance of 2.5 m from the centre of the...

Homework Statement A vibration platform oscillates up and down with an amplitude of 10.4 cm at a controlled variable frequency. Suppose a small rock of unknown mass is placed on the platform. At what frequency will the rock just begin to leave the surface so that it starts to clatter? Homework...

Hi guys, I am looking for a small and light air valve that can be activated by the arduino platform and can run on batteries. Once the valve gets the “go”signal it needs to switch (speed doesn’t matter) from a closed to an open position. The pressure to handle is low, i.e. <2 bar. It only needs...

So, the classic scenario: Person on frictionless rotating platform, holding a spinning bicycle wheel with vertical axis of rotation. Flips it over, and the platform spins in the direction the wheel was originally spinning. Angular momentum is conserved. My question is: Is there any way to...

Homework Statement I have a cylinder of mass M and radius R, it stands over a platform of mass m; the platform stands over a no-friction floor. There is a given force F on the platform, directed horizontally on the right. The coefficient of static friction between the cylinder and the platform...

Homework Statement Homework Equations ƩF = mA T=rxF The Attempt at a Solution Using sum of forces, I found: ƩF=mA 150lb + 50lb - F1 - F2 = 0 (calling the support on the right "1") ƩT1 = 0 But I'm a little confused on where to go from this point. Any advice?

Because of size constraints in my room, I need a platform for my queen size bed that is the exact footprint of the bed (60" x 80"). I've decided to attempt to build it however I have no experience with this and hopefully someone can point out any flaws in my plans. I've attached an image...

Hi all, Was told by an engineer at a tech startup to inquire here for anyone interested in discussing/solving/working on this problem. Basically, I am looking to crawl and index all images on a certain part of the web (yet undefined which part) and to be able to run a reverse image search...

Hi all, I am planning to build solar tracker which will have a platform that rotates about vertical axis according to sun. The platform should have max tangential speed of 1.03 m/min and min tangential speed of 0.017 m/min. The platform has a mass of 4 tonnes and radius of 10 m and can be...

hi, there are 8 versions of c-130 .what is the platform that is common in them? Can anyone help?

A cylindrical tin, full of water, is sitting on a platform. What is the maximum acceleration of the platform that will not cause the can to tilt? The dimensions of the tin are known. I'm unsure how to approach the question first off. My reasoning so far has been along the line of this...

Hello everyone, I am considering a project which involves buoyancy. The core component of the product is 4 meters by 4 meters (squared, solid platform) and approximately 30 cm high. This platform is supposed to float on a water surface, most likely lakes. Furthermore, the platform should...

Homework Statement An amusement park ride consists of a rotating circular platform 9.87m in diamter from which 10kg seats are suspended at the end of 2.59m massless chains (L). When the system rotates, the chains make an angle of 39.3 degrees with the vertical. The acceleration of gravity is...

Homework Statement A 27.5 kg person stands on a 55 kg platform. He pulls on the rope that is attached to the platform via the frictionless lower-right pulley. He pulls the rope at an angle of 29◦ to the horizontal, as shown in the figure below. Assume: g = 9.8 m/s2 . Ignore friction. The...

Unreal. Could it have been sabotaged? They do not know yet if it is leaking oil. The people on the rig are ok. http://news.yahoo.com/s/ap/us_gulf_rig_explosion

Google invested $100-200 million in social gaming company. What does it mean for the future of gaming?http://stats.wordpress.com/b.gif?host=virtualnavigator.wordpress.com&blog=11498882&post=123&subd=virtualnavigator&ref=&feed=1 More...

Homework Statement A 78kg man, standing erect, steps off a 2.6m high diving platform and begins to fall from rest. The man comes to rest 1.7s after reaching the water. The acceleration of gravity is 9.8 m/s^2 What average force did the water exert on him? Answer: 1091.94 N Homework...