Height Definition and 1000 Threads

Homework Statement Determine the minimum height of a wall mirror that will permit a 6ft person to view his or her entire height. Sketch rays from the top and bottom of the person, and determine the proper placement of the mirror such that the full image is seen, regardless of the persons...

Hello, I'm trying to simulate a projectile movement (without any air friction). But my projectile parameters are not conventional. I know : The initial height (y0) The initial velocity (v0) The maximum horizontal travel distance (d) The maximum height (h) I need to find ...

Homework Statement Been working on this for the past hour or so and seem to be going in circles; finally decided to call in the cavalry: You land on an unknown planet somewhere in the universe that clearly has weaker gravity than Earth. To measure g on this planet you do the following...

Homework Statement A handball is projected at an angle of 30 degrees with the horizontal from a 20 meter tower with an initial vertical velocity of 10 ms and an initial horizontal velocity of 20 ms. Find the total time of flight. Homework Equations The Attempt at a Solution I...

Homework Statement A baseball is thrown with an initial velocity of 20 ms at an angle of 30 degrees with the horizontal. How high did it go if it was released and caught 2 meters from the ground? Homework Equations The Attempt at a Solution 0=Vi^2 + 2ad 0=(20Sin30)2 + 2 X...

Homework Statement A child of mass 30 kg runs up a flight of stairs in 6 seconds. The top of the flight is 3 metres above the bottom, and at the top he is running at 2ms^-1. What average power does he need to produce? The Attempt at a Solution This is one of the first exercises I...

Homework Statement Nicole throws a ball straight up. Chad watches the ball from a window 6.10 m above the point where Nicole released it. The ball passes Chad on the way up, and it has a speed of 11.0 m/s as it passes him on the way back down. How fast did Nicole throw the ball? Homework...

Hi, I have the following problem that I would like to solve by using the 'fft' function in matlab. Some background on the problem: The evolution of sea surface height is given, to first order, by \eta_o(x,t)=A\cos\left(kx-\omega t\right) From this, we see that there are three parameters...

Homework Statement question is in the diagram. basically I am not sure how to use the specific gravity and convert it into pressure. Homework Equations P=p(rho)gh The Attempt at a Solution -

Homework Statement A 7500-kg rocket blasts off vertically from the launch pad with a constant upward acceleration of 2.25 m/s^2 and feels no appreciable air resistance. When it has reached a height of 525 m, its engines suddenly fail so that the only force acting on it is now gravity. (a)...

Homework Statement The attachment shows the problem. The normal force at the top of the loop is 3 g's (as in g-force). Homework Equations PE = mgh KE = .5mv2 Fc = \frac{mv2}{r} PE + KE = PE' + KE' v = \sqrt{2gh} The Attempt at a Solution The normal force would be: 30 * mass...

Like people saying that drinking milk and sleeping right will make one grow taller, but is there seriously any effect at all? It's a genetics right? They say jumping or stretching make you taller, is that true?

Homework Statement An Earth satellite is to be put into orbit at a height of 2 Mm above the Earth's surface. Determine the velocity it must have. Make the following assumptions: (a) the orbit is circular; (b) the Earth is a sphere of radius 6•37 Mm; (c) gravity decreases as an inverse...

Homework Statement The triangular prism looks like this: http://www.korthalsaltes.com/photo/triangular_prism.jpg The triangles are "isosceles" triangles though, with the base facing down. However, this one is open on the bottom. They want me to find the height of the prism, when the area is as...

Ok, so I am trying to build myself a small water tank (about 1 L) with 2 tubes coming from the top. The first one goes all the way down to the bottom (thus in the water) and acts as the outtake. The second one is an air intake where the air pressure is regulated, say 5 psi. Now, I want to be...

This problem has 2 stars in my book, which means it is supposed to pretty difficult. I got the answer fairly easily and am worried that maybe I missed something important and thus got the incorrect answer too easily. No answer is provided to self-check my answer to see whether or not I am...

Homework Statement so if the original object is 4.6 cm tall located at x = 0 and it's a concave mirror distance from C to the object is 16 cm and Radius of the mirror is 12 cm The Attempt at a Solution to find the position of x image i got 9.6 cm then for magnification i...

Homework Statement A lens forms an image of an object. The object is 16 cm from the lens. The image is 12 cm from the lens on the same side as the object. (a) What is the focal length of the lens? Is the lens converging or diverging? (b) If the object is 8.5 mm tall, how tall is the image...

Well what do you guys and girls think. Does height play any role in attractiveness, offer any advantages in dating especially if you're a guy? It seems like for girls, they have to worry about how big their breasts, and "bums" are and for guys it's about how tall they are. Some girls...

the image of a tree just covers the length of a plane mirror 4.3 cm tall when the mirror is held 32 cm from the eye. The tree is 28 m from the mirror. What is the height of the tree? so I set up a ratio .043/.32=(28-.32)/h and solved for h and got 205 meters, but I am not sure if...

Firstly, I've been going over your forums for about fifteen minutes, and am taken aback by the intellect I have come across. I never took physics, but wish I had. Right out of high school, I went into construction, and never got the chance to go to college. I was always good at everyday Algebra...

Homework Statement A man drops a stone into a water well on his farm. He hears the sound of the splash 3.18 s later. How deep is the well? The acceleration due to gravity is 9.8 m/s^2 and the speed of sound in air is 316 m/s. Answer in units of m. Homework Equations x - x0 = v0t + (1/2)at2...

Hi, How do I find the height of the triangle , the triangle is set at 30 degrees and the length is 5 meters any help would be appreciated.

[b]1 A particle is projected with a velocity of 146m/s at an elevation of 35degree. max height= 357.8, t=17.1s horizontal distance= 2041.8m the question is find the velocity and direction of motion at a height of 120m i got v= 137.72, but what is the meaning of the direction of motion at...

Homework Statement I'm trying to calculate a value for gravity based on a known jump height and time. It's working when the take-off and landing heights are the same but I'm struggling for a solution if the landing point is higher than the take-off. I'm more interested in understanding a...

I'm taking an introductory geology class and am having big trouble with the math questions, as it's been many many years since I last took math classes. I am to use Archimedes Principle to calculate the thickness of continental crust beneath a certain coastal geographical point (at sea level...

Homework Statement I'm doing research with a professor at my college this summer on energy modeling for an electric vehicle. We're trying to figure out a way to make a model to predict how much energy an electric vehicle would need in order to do a certain path, but that requires testing of...

A roller coaster (475kg) passes point C with a velocity of 10.0 ms-1, calculate the velocity of the roller coaster at point A. mass = 475 kg velocity at C = 10 ms-1 height at A = 30m height at B = 0m height at C = 25m height at D = 12m Ep = mgh Ek = 1/2mv^2 The trolley is moving...

The scenario: I have a bag containing 3L of water, attached to a tube with the end placed on the floor (or a fixed height from the floor e.g. a bucket placed on top of a chair at 60 cm). I plan to hang this bag at heights of 100 cm, 120 cm, 140 cm, etc... until say about 200 cm from the floor...

Homework Statement When a 5kg mass is hung vertically on a light spring the spring stretches 3 cm. how much work must a external agent do to stretch the spring 4 cm from its equilibrium position? Because I am guessing it is hung vertically from the ceiling?

To calculate the height of a crane which is on top of a building, dennis measures the angle of elevation to the bottom and the top of the crane. these were 62 degrees and 68 degrees respectively. if the building is 42 metres high find the height of the crane. I'm asking for a friend, excuse...

To calculate the height of a crane which is on top of a building, dennis measures the angle of elevation to the bottom and the top of the crane. these were 62 degrees and 68 degrees respectively. if the building is 42 metres high find the height of the crane. I'm asking for a friend, excuse the...

Homework Statement "A boy throws a rock with an initial velocity of 3.13 m/s at 30.0 degrees above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory?" vi = 3.13 m/s tmax height = ? vf = 0 m/s (at max height) a = -9.8 m/s2 Homework...

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 0.80 s, and passes it again on the way down 1.6 s after it was tossed. What is the height of the power line and the initial speed of the ball...

Homework Statement A 0.21 kg rock is projected from the edge of the top of a building with an initial velocity of 7.82 m/s at an angle 56 above the horizontal. Due to gravity, the rock strikes the ground at a horizontal distance of 10.5 m from the base of the building. How tall is the...

Homework Statement A toy rocket, launched from the ground, rises vertically with an acceleration of 23 m/s2 for 11 s until its motor stops. Disregarding any air resistance, what max- imum height above the ground will the rocket achieve? The acceleration of gravity is 9.8 m/s2 . Answer...

I am working on a project that will use cylindrical neo magnets. Is there an ideal height to diameter ratio for neo magnets?

Homework Statement The gondola ski lift at Keystone is 2830 m long. On average, the ski lift rises 14.6 above the horizontal. How high is the top of the ski lift relative to the house?Homework Equations The Attempt at a Solution Drew the picture, did 2830cos(14.6) but don't know what to do next.

Homework Statement One mass, m1 = 215g, of an ideal Atwood machine rests on the floor 1.10m below the other mass, m2 = 255g. (a) If the masses are released from rest, how long does it take m2 to reach the floor? (b) How high will mass m1 ascend from the floor? Known variables: m1 = 215g...

What determine the relative heights of the k-alpha, k-beta peaks in the X-ray production curve?

On the surface of the sun the acceleration due to gravity is approx 0.25km/s². A mass of gas forming a solar prominence rises from the sun's surface. If only gravity is considered, what must its initial upward velocity be, if it is to reach a height of 24000km above the surface? I can't...

Homework Statement The attempt at a solution To find the height of mercury I have used the following equation: P _{gauge}=\rho _{air}\cdot g\cdot h_{air}+\rho _{Hg}\cdot g\cdot h_{Hg} where P _{gauge}=3.75 KPa So I solve for h_{Hg} and get 2.8 cm. I don't think this is...

Homework Statement Question 5 Figure 5.1 Figure 5.1 shows a nozzle with a jet of liquid 30 mm in diameter with a density of 850 kg.m-3 hitting a plate that has hole of 10 mm diameter in it. The jet of water requires a force of 50 N to hold it in place. (a) Assuming frictionless...

Hi A surveyor is attempting to calculate the height of a Point P, on a building by taking measurements on a horizontal level ground. From a point A, the angle of elevation of P is 30 degrees. He then advances 20 m towards Point P, Point B, and measures an angle of elevation of 45 degrees...

Homework Statement In a large underground cave, the concentration of helium at the base is measured to be 1.00x10^-4. If the air in the cave is at a constant temperature of 10 degrees-C, what is the concentration of helium at the top of the cave, 300m higher? Answer: 1.03 x 10^-4...

Hi I'm new to the physics forum as this is my first post so apologies for any mistakes. I have a question relating to projectile motion that i don't understand the question is: The chipping machine is designed to eject wood chips at Ui = 7.6 m/s. If the tube is oriented at 30 degrees from...

Homework Statement Design projectile motion simulation and produce the max height, inital and final velocity, range, and time of flight. must use digital or photographic tech to record events and assist in the experiment> Okay so I've designed a half projectile motion simulation. A ramp...

Homework Statement two divers jump on a diving board, who will jump highest, Weights of divers are known and velocity they are jumping at. I'm stuck finding the right formula, I know the board has to deform, stored energy has an influenece. I think its a basic question but my brain has...

A rocket of mass m=1.20x10^3 kg is launched vertically upward from the Earth's surface with an initial speed v0 = 7.00 km/s. Calculate the maximum height H of point A above the Earth's surface at which the rocket will momentarily come to rest, before it starts falling back on the earth. So I...

Homework Statement m=10k h=12m F=200N Homework Equations a=v/t F=ma The Attempt at a Solution I cannot find the remaining equations to completely work the problem.