Kinematic Definition and 395 Threads

I have been looking into how the overall viscosity of a liquid/gas is related to kinematic and dynamic viscosities. I have used nwater = 1e-3 Pa.s nair = 17.4e-6 Pa.s densitywater = 1000 kgm^-3 densityair = 1.3 kgm^3 and kinematic viscosity v = n/density So vair ~ 1.4e-5 vwater ~...

An elevator ascends from the ground with uniform speed. At time T1 a marble is droped from the floor and hits the ground T2 seconds later. Find the height of the elevator at time T1? Clue T1=T2=4s. Z0=V0z*T1 Z=V0z*T2 - (g*(T2)^2)/2. Where Z0 is the height at T1, Z is taken to be...

pls see attached file. so i thought i could use this eqn: aA = w2 AO en + alpha AO et but when i try to work out w, something goes wrong. i do: w = 7.16605 (normal velocity i found by having the given velocity as a y coordinate one, then resolving for normal/tangential) / 0.25. but...

Homework Statement A car accelerates uniformly from an initial velocity for 6s. The displacements in the 3rd and the 5th seconds are 12m and 18m respectively. Find the acceleration and the initial velocity of the car. (Answer: 3m/s^2 , 4.5 m/s) Btw this from a first year physics course...

Homework Statement A .1 m ramp is sitting at the edge of a horizontal surface that is 1 m from the ground. One ball is resting at the top of a ramp and another ball is resting at the bottom of the ramp where it is flattened. Each ball has a mass of .05 kg. Ball one is released and hits ball...

Mechanics Kinematic General Concept question, not a numerical!? I'm really confused concerning the positive direction and the acceleration taken while concerning the motion of the ball! Well, the main thing that i wanted to ask is that if 2 balls are been projected at the same time in two...

Homework Statement Let a and b be two given orthonormal vectors around a fixed point O. The motion of a continuum is defined by the following velocity field: [tex] v(M) = \alpha \vec{a} (\vec{b} . \vec{OM}) \\ [\tex] where [tex] \alpha [\tex] is a known positive constant. 1...

A motorcycle officer hidden at an intersection observes a car driven by an oblivious driver who ignores a stop sign and continues through the intersection at constant speed. The police officer takes off in pursuit 1.95 s after the car has passed the stop sign. She accelerates at 4.2 m/s2 until...

A person runs 100 m in 9.77 s. Maximum speed was reached in 3 s, then maintained for the rest of the time. What was the acceleration during the first 3 seconds? I know that I can find the average velocity, which is 100 m/9.77 s, and i know that initial velocity is 0 m/s. I don't know how to...

Vectors and 2D Kinematic Question! On the Apollo 14 mission to the moon, astronaut Alan Shepard hit a golf ball with a golf club improvised from a tool. The free-fall acceleration on the moon is 1/6 of its value on earth. Suppose he hits the ball with a speed of 25 m/s at an angle of 35° above...

Homework Statement A stone is flung straight up from a point 1.50 m above the ground and with an initial speed of 19.6 m/s. a. What is the stone's maximum height above the ground? b. How much time passes before the stone hits the ground? Homework Equations The four kinematic equations...

Hey guy, I'm working at my school to ID our collection of kinematic models and make signs for explaining them. I have them almost done, but there are a few I can't find in any of the books, can you guys take a look at the attached and linked pictures and see if you can ID them?

Homework Statement a man dropped a stone into a can that is 120m deep. if the temperature of the air is 20degree celsius. how long would it take for a man to hear the sound when the stone hit the can? Homework Equations d=Vi*t + 1/2*a*t^2 The Attempt at a Solution since i know that...

In this particular act, a man is shot out of a cannon with an initial velocity of 10 m/s at an angle of 60 degrees onto a net at some distance away. The cannon is 6.5m above the ground, and the net is 2.5m above the ground. How long does it take for the man to land on the net? how far is the...

Homework Statement Runner A runs at 6.0 m/s for 10 s. How far does he go? NOTE: THE ANSWER IS 60 m BUT I DON'T KNOW HOW IT GOT TO THAT. Homework Equations V=Vo + at X=1/2(Vo +V)T X=VoT + 1/2at2 V2=Vo2 + 2ax (If a 2 is after a letter then it means squared) X=displacement...

Homework Statement Equation for a particle moving in one dimension with potential energy U(x): t=\int1/\sqrt{2(E-U(x))/m} , integrated from x0 to 5x0 Suppose U(x)=c/x for x>0. Calculate the time for the particle to move from x0 to 5x0, starting from rest at x0. Leave the answer in...

What is the difference between Kinematic coupling in Abaqus and Rigids in Nastran? Why it is named as Kinematic Coupling... what is the physics behind the word kinematic and rigids?

Homework Statement A car driving at a constant speed of 75 ft/s passes a police car that is initially at rest. If the police car decides to give chase A) What rate would the police have to accelerate to catch up with the other car in 12 seconds? B) What is the police car's speed at the end...

Homework Statement A helicopter carrying Dr. Evil takes off with a constant upward acceleration of 5.0m/s². Secret agent Austin Powers jumps on just as the helicopter lifts off the ground. After the two men struggle for 10.0s, Powers shuts off the engine and steps out of the helicopter...

Homework Statement 1. A car driving at a constant speed of 75 ft/s passes a police car that is initially at rest. If the police car decides to give chase A) What rate would the police have to accelerate to catch up with the other car in 12 seconds? B) What is the police car's speed at the end...

Homework Statement Ok, so i have a test on Kinematics Grade 11 coming up on monday and i want some practise on Challenging Word Problems. Can anyone give me some problems to prepare for mondays test and help me through the process like which formula i use and stuff. Homework Equations...

Here is the problem that I am having trouble with (It probably is a no brainer, but i am a bit rusty- not a bit actually, a lot!). Here is the question: A student stands at the top of a building to perform a kinematics experiment. He throws a red ball directly upwards with an initial speed...

Homework Statement When do i use: (delta)Y=Viy+(1/2)ayt2 Compared to... (delta)Y=Viy-(1/2)ayt2 What tells me if I am going to be using (+) or (-)

Ok, pretty basic Physics-101 question. However, I don't understand why my method for solving isn't working. Homework Statement Two cars. Car one is at rest, while the car two is traveling at a constant 16.66 m/s (given as 60 km/hr). At the moment car two passes car one, car one begins...

I already typed a long drawn out post, so I am going to simplfy it. I am having trouble using algebra to rearrange equation. For Example, v=d/t And so, to solve for both t and d, I do the following vt=d/t x t vt=d vt/v=d/v t=d/v I have difficulty with most if not all the other...

Homework Statement A rectangular block of length L is traveling on a smooth surface at velocity u. When it encounters rough ground with coefficient of friction mu, it decelerates to a stop. What is the time taken for the rectangular block to stop?Homework Equations F= (mu)mgThe Attempt at a...

Homework Statement What is the thrown angle of a body with a weight w, to make the maximun height equal to the horizontal lenght. Also exists a horizontal wind's force F that acts over the body? The Attempt at a Solution I think these are the relations, or i am wrong? 1...

Homework Statement An arresting device on a carrier deck stops an airplane in 1.5s. The average acceleration was 49 m/s^2. What was the stopping distance? What was the initial speed? Homework Equations ? [b]3. The Attempt at a Solution [/b DONE! :D No need for help anymore :D

For one degree of freedom, the mechanism is constrained .. What does "mechanism constrained" really mean ? Any example ?

I was just pondering today how the kinematic equation for position looks like a taylor expansion. x = x0 + dx/dt *t + (1/2)*d2x/dt2*t2 I believe it continues like that, exactly like a taylor expansion does, so the next term would be (1/6)*d3x/dt3*t3 If it is indeed a taylor expansion, what...

Homework Statement A body of mass m is thrown upward with intial velocity u, in a medium which exerts a resistance force of mkv. Express, in term of g, k and u, the time taken for the body to reach its maximum height Homework Equations The Attempt at a Solution a = -g - kv...

Homework Statement A particle of mass m falls from rest; the resistance of the air when the speed is v is kv2 where k is a constant. Show that after a time t, the velocity v and the time t are related by the equation t = V/2g ln[(V + v )/(V - v)] where V2 = mg/k Homework Equations...

Homework Statement A particle of mass m is projected vertically upwards, with an initial speedo of u, in a medium which exerts a resistance of magnitude mkv, where k is a positive constant and v is the speed of the particle after time t. Express, in terms of k, g and u, the time taken for the...

In Euclidean Space-Time, the kinematic equation is: s^2=g_{\mu\nu}x^{\mu}x^{\nu} am i correct if i write : K^{\mu \nu}_{\mu \nu}=g_{\mu \nu}x^{\mu}x^{\nu} where s^2=K^{\mu \nu}_{\mu \nu}? thank you very much

Okay, we all know that ΔX = ViT + 1/2AT^2 Say I drop a stone from rest and I want to find its distance at a given time knowing the acceleration. Since the initial velocity is zero and its accelerating vertically we can say. ΔY = 1/2AT^2 ΔY = (AT^2) / 2 <------------------------- Keep in mind...

can u explain what is kinematic indeterminancy?

Hello, Just wondering if someone can help me make sense of something. I realize it's probably a simple problem, but my math skills aren't the best and I can't see through it. I'm trying to end up with this kinematic equation: X= Xo + Vo(t-to) + 1/2(a)(t-to)^2 And to do this the...

Homework Statement The driver of a vehicle on a level road determined that she could increase her speed from rest to 50 mph in 35 sec and from rest to 65 mph in 95 sec. Assume that acceleration varies linearly with speed (with a non zero intercept). Determine the max acceleration in each case...

Homework Statement A mountain climber stands at the top of a 50.0m cliff hanging over a calm pool of water. The climber throws two stones vertically 1.0 s apart and observes that they cause a single splash when they hit the water. The first stone has an initial velocity of + 2.0 m/s. a) How...

Homework Statement David is driving a steady 30.0 m/s when he passes Tina, who is sitting in her car at rest. Tina begins to accelerate at a steady 2.0 m/s^2 at the instant when David passes. a. How far does Tina drive before passing David? b. What is her speed as she passes him? Velocity...

If I drop a ball, how far will it fall in 2 seconds? ΔX = ViT + 1/2AT^2 ΔX = (0)(2) + 1/2(9.8)(2)^2 ΔX = 19.6 m I tested this, and there is no way an object falls 19.6 m in only 2 seconds. Think about it. Drop something right now and it will only fall like 1 meter in one second. I don't...

Homework Statement An observer on the Earth observes the angle subtended by the diameter of the moon to be 0.009199 radians. If the moon is 234,800 miles away, what is its diameter? Homework Equations The Attempt at a Solution Not quite sure where to begin with this one. I think it...

Homework Statement Knowing and understanding the kinematic equation's variables x1, x0, v0, t, and a, how has .5 been incorporated into the equation? I realized this unknown during lab. Now, as I've nearly completed my analysis, I find that the values I've derived for acceleration should be...

Homework Statement Given the reactions: p + 9 Be --> 10B + "gamma" p + 9 Be --> 9B + 1n p + 9 Be --> 9Be + 1p p + 9 Be --> 8Be + 2H p + 9 Be --> 7Be + 3H p + 9 Be --> 6Li + 4He Calculate: a) Q-value b) kinematic threshold energy of the proton...

Looking For Help to derive the kinematic equation for the 4-bar linkage shown; (to find the angular position of the cylinder at different values of theta )

The equations for linear motion I've memorized are: 1.) v = u + at 2.) v^2 = u^2 + 2as 3.) s = ut + 1/2(at^2) v = final velocity, u = initial velocity, a = acceleration, t = time, s = displacement In an example my physics teacher uses the equation x = x0 + (v^2-u^2)/2a I'm assuming he...

Homework Statement http://img691.imageshack.us/img691/2702/drawing1.png A 1kg block is suspended from a rope that wraps around a pulley where it is pulled by a 10N force. The pulley is a disk with mass 50g and has a diameter of 4cm. Assume enough friction that the rope does not slip but...

Homework Statement A car is traveling along a highway with a speed of 25m/s when the driver sees an obstruction 180m directly ahead. It takes the driver 0.80s to react and begin breaking. A) How long will it take the car to stop once brakes are applies, provided the car stops just before...

I'm in a physics 201 course and very confused about the kinematic equations. Is there anybody out there who can describe what each one means? Thanks, Mike

A car is decelerating uniformly. Its velocity changes from 30m/s to 15m/s in 75m. How much further will it travel before it comes to rest? - Please, i need a detail answer. Thanks!