Race Definition and 220 Threads

#1 A 5 g bullet leaves the muzzle of a rifle with a speed of 320 m/s. What force (assumed constant) is exerted on the bullet while it is traveling down the .82 m long barrel of the rifle ? -------------------------- m = .005 kg v (initial) = 320 m/s d = .82m F = ma but i don't know how to find...

Homework Statement Ed, the leading runner in a race taking place along a straight track, is traveling at his top speed, a constant 10.0 m/s. He has been 4.1 m in front of Harry, his chief rival, for the last 10.0 s. But aware that Ed will hit the finish line in 15.0 s, Harry puts on a burst of...

Homework Statement Cars A and B are racing each other along the same straight road in the following manner: Car A has a head start and is a distance Da beyond the starting line at t=0. The starting line is at x=0. Car A travels at a constant speed Va. Car B starts at the starting line but has...

Hello, Just after a bit of help with the following, I have a solution but don't think it is correct due to me not including the lap size. Runner A runs at 6.25m/s per sec and runner B at 4.39m/s per sec in a 1500 mtr race. a, calculate te distance at which runner A laps runner B. B, if...

Hi friends SHAASTRA 2007 (IIT MADRAS,INDIA) brings you an opportunity to earn a lot of cash and become famous . Participate in FIRE n ICE event where you have to make a small hovercraft and compete with others. For more information look at the link below...

What is the chance of predicting the out come of a race like the Grand National?

Homework Statement Friction coefficient between an athlete's shoes and ground is 0.9 . Suppose Superman wears these shoes and runs a 50m race.There is no upper limit on his capacity of running at high speeds . Starting from rest, what will be the minimum time before he finishes the race ...

My mum told me this one, it's pretty cool :). The red car and the blue car are having a race. The red car, which has a top speed of 70mph has a 20 minute head start over the blue car, which has a top speed of 80mph. Assuming that top speeds are reached the very instant a car starts, and...

So is anyone watching the playoff race? 7 teams divided by 4 points fighting for 4 spots with 5-6 games left (1 spot guaranteed to ATL/TB/CAR) ATL 88, NYR 87, TB 86, MTL 86, CAR 84, TOR 84, NYI 84. HEH i hope it turns out to be ATL MTL, TOR and TB but it looks like it NYR will oust...

https://www.physicsforums.com/showthread.php?t=160610 Continuing off this problem.. My teacher wrote the solution on the board (and conveniently went to the hospital before our period). Problem again.. Homework Statement The velocity of the transverse waves produced by an earthquake is 8.9km/s...

Homework Statement The velocity of the transverse waves produced by an earthquake is 8.9km/s while that of the longitudinal waves is 5.1km/s. A seismograph records the arrival of the transverse waves 73s before that of the longitudinal waves. How far away was the earthquakes?Homework Equations...

whoa for the biggest 1st post bump ever I've been involved in a few discussions over racism this week, so it's all new and fresh to me; well, I decided to post my thoughts here, for historical reference. This thread was looking for "scientifical" definition of human races that could be used in...

:cry: Alright I need help drawing the diagram... I know what I'm doing and a lot of the information but I need help with the diagram. A three car race track has sensors in each lane at the finish line. As the cars cross the finish line their respective sensors respond and send a signal to a...

The Great Marble Race Physics Project Due: Nov. 13 The project is a display that demonstrates several concepts of mechanics. It will consist of a ball and a series of tubes or track that send the ball through motions that illustrate the physics concepts. At least 6 different concepts will be...

Is there anyone else here in PF that follows F1? I am completely obsessed with it, it is my dream to race in F1.:rolleyes: I can't believe that Michael Shumacher is retiring!??!??! I watched his final race two sundays ago and wow, he is simply amazing. On the first lap one of his tires blew...

Race Car Acceleration Rates? Hi There, I have been on the web for two weeks now trying to find an answer to my situation. There are no calculators that I can input the numbers below into find out what is best. The rule in road racing is he who can accelerate the hardest out of the corner...

explain the following in f=ma a)a racing car has a powerful engine and is made of storng but light weight material b)a car with a small engine can still accelerate rapidly please help me i need model answers thanks soooooo much:biggrin: :cry: :biggrin:

Say a father who has a mass that is two times that of his son is racing against him, and his kinetic energy is half of his son. When the father increases his speed by one m/s, the kinetic energies are equal. I do this: M = mass of father V = velocity of father 0.5MV^2 = 0.5(0.5mv^2)...

I am working on a model of a solar powered drag race. The race: 250 meters, no incline, initial velocity = 0. Classical physics gives us the following equations (ignores aero and rolling drag and wheel rotation): Velocity as a function of time V = (2Pt/M)^.5 P = power, M = mass...

Do you think that intelligence and creativity are based on race? If so, why? If not, why not?

Another "dark" horse in the MOND race I'm glad there are several competing alternatives to dark matter. Bekenstein's TeVeS doesn't have the field to itself. this appeared today: http://arxiv.org/abs/astro-ph/0605322 Dark energy, MOND and sub-millimeter tests of gravity I. Navarro, K. Van...

The race is not to the swift or the battle to the strong, nor does food come to the wise or wealth to the brilliant or favor to the learned; but time and chance happen to them all. I'm wondering what this "poem" really means. Is it that the race is for everyone who uses up his/her time...

The situation is this: Two space vehicles A and B are doing a race in space. A is in front of B and they are both in orbit around the earth. For simplicity let this orbit be a circle (i.e. neglectable eccentricity). Now, B wants to get past A, that is, B wants to cross the "line" connecting the...

[FONT="System"]Okay, so here's the competition: We will be given a spring that can stretch to no more than 40 centimeters in length. That spring has to be used to power some type of vehicle to move as far and as slow as possible. Our score will be determined by this: time*distance=score...

Hi all! It's me again. I asked about how the wing of a design car should be designed before. Thanks for all your replies. I would like to have a good reference book for me to start from scratch learning how to build a race car, do you guys have any recommendation? p.s. I major in...

Does race exist or is it a social construct? After reading only a few pages of "Race and Intelligence", I am leaning towards the latter. However, I have also noted that a scientist I admire, Dawkins, believes in race. However, the reasons why he does, according the wikipedia, are contained in an...

I have been thinking of the evolution of the human race over time. Obviously, environmental factors have prevented those with detrimental traits from passing them on, bringing us to our current form. However, with the amount of technological advances in our current time and in the near future...

The minute and hour hand of a watch meet every 65 minutes. How much does the watch lose or gain and by how much?

Was there ever a race of giant people ? i have come across sites that claim they existed but all the evidence seems to have disapeared.

Can someone please explain the reason as to why a race of humans cannot start with one man and one women? This silly idea keeps popping up with creation people and I can't see that this is even what the Bible holds true. But I'd like to hear as to why this can't be true from a biological point...

"A child's toy race car travels across the floor with a constant velocity of 2.10m/s. if the car possesses 14.0 j of kinetic energy, find the mass of the car." How do i do this question? Am i supposed to use ek=eg or something else?

In a race down inclined plane why does a cube reach bottom first? The other object is a solid cylinder. The cylinder rolls without slipping, and the cube slides. The cylinder has radius R, and a cube has radius R. Does this depend on the mass of the objects? Is it because since the cube...

The last couple days in Sociology have been very argumentative. Here's why Why Race Exists As a Valid Means of Classification We humans have created a device to help classify and recognize the physical differences between living organisms. This identification system was created in order...

Bon Jovi challenges Kurt Kobain to a five mile car race. Kurt Kobain commences the race at a constant speed of 22 miles per hour. Bon Jovi waits precisely three seconds after Kobain has traversed 3/5 mile and starts his car, covering every xth mile at the rate of 5/2*3^x miles per hour. Who is...

Not asking for an answer, just point me in the right direction please: In order to qualify for a racing event, a race car must achieve an average speed of 278km/h on a track with a total length of 1260m. If a particular car covers the first half of the track at an average speed of 209km/h...

Ignoring the if, when, and how of contact with an alien race, what would the social stigmata be of this event? Suppose that we receive radio signals from Race B (roughly equivalent in technological development) that originate several light years away in 2010. How would our society be forced to...

It seems GWB has given green signal to US Air Force to develop space weapons. Is it really true and is it going to trigger an arms race. What are the other countries doing? I don't think UN would be of much help! :smile:

A race car moves such that its position fits the relationship x(t) = (4.4 m/s) t + (0.91 m/s^3) t^3 (yes cubed) where x is measured in meters and t in seconds.Approximate the instantaneous velocity at t = 2.6 s, using a time interval of 0.2 s. Answer in units of m/s. i am just stuck and...

Is There A More Evolved Race? you always here about blacks being the natural athletes and what not. I am sure you see a lot of asians being very flexible, but i wanted to know if physically speaking, there were a more evolved race out of the bunch of us. has there been any research done about this.

In physics class, we had a soup can race to see which can of soup would get to the bottom of the ramp first... the length or height of the ramp was given but there were 2 kinds of soup used one was french Canadian pea soup and one was chicken broth the chicken broth got to the bottom...

What will be the last existing vestige of the human race? How shall it compare to the first such evidence? Will it be characteristic of humanity in general?

If the frictional forces are independent of the area of the tire in contact with the road, what motivates this choice?

Why exactly do race cars have their tires heated before a race?

Technology today is so focused on efficieny, proficiency and producivity. Cloning to create better humans, faster transportation, longer work-days and computerised everyday experience. Is it worth it? For anyone who believes in evolution: Have you created machines that we ourselves cannot...

A particular race car can cover a quarter-mile track (402 m) in 6.27 seconds, starting from a standstill. Assuming the acceleration is constant, how many "g's" does the driver experience? This has to be a really easy problem as I am given the m and the sec but I can not figure out what...

Ok this is another problem I am having trouble with. In a 100 m race, Maggie and Judy cross the finish line in a dead heat, both taking 10.2 s. Accelerating uniformly, Maggie took 2.10 s and Judy 3.10 s to attain maximum speed, which they maintained for the rest of the race. What was Maggie's...

1. A rabbit and a tortoise compete in a 100 meter race. The tortoise moves at a uniform speed of 10 cm/s. The rabbit took a nap for 16 minutes. After the rabbit wake up, he accelerates at a uniform rate of 0.15 m/s^2. a) Draw a time vs. velocity of the motion of the tortoise and the rabbit...

In a relay race, each contestant runs a distance 24.8m while carrying an egg balanced on a spoon, turns around, and comes back to the starting point. Edith runs the first distance 24.8m in a time t1=19.3s . On the return trip she is more confident and takes only t2=time 15.1s . What is her...

Ethn Dis. 2004 Summer;14(3):389-98. Race/ethnic and sex differentials in body mass among us adults.[/size] Denney JT, Krueger PM, Rogers RG, Boardman JD. Population Program, Institute of Behavioral Science, and Department of Sociology, University of Colorado, Boulder, Colorado...

some people at PF like to talk about race: either to attack and belittle the notion, and deplore others using the word, or contrariwise to defend it. So a lot of information is flying around and you can learn a lot from the conversation. I've learned things I didnt know somebody, Moonbear...