what is meant by AVERAGE SPEED?
915787
I see the point of your question. Speed itself is the average velocity, so the term really means 'average average velocity'.\nI'd say average speed means bad english bad english, or is it bad bad english?\nô¿ô
184211
Every answer I've seen to this question so far has been dead wrong (or at least mostly wrong).\n\nTo compute average speed in any word problem, figure out the total distance traveled, total time traveled, and then divide. average speed = (total distance)/(total time)\n\nTotal distance traveled here is clearly 40+50 = 90 miles.\n\nTotal time traveled is a bit trickier, so we'll look at this one leg at a time. For the first leg of the journey, we went 40 miles at x mph. Time elapsed is the distance traveled divided by the rate of speed, or 40/x. Does this check out? Let x be a nice easy number like 20 mph and check it for yourself.\n\nThen the time for the second leg will be 50/(x+10), and total time is 40/x + 50/(x+10).\n\nNow we've got total distance and total time, so we just divide to get the final answer:\naverage speed = 90/(40/x + 50/(x+10))\n\nWe can pick a value for x to see if this makes sense. Let x = 40. Then on the first leg we traveled 40 miles at 40 miles an hour (so clearly 1 hour) and on the second leg we traveled 50 miles at 40+10= 50 miles per hour (so another hour). Total time is therefore 2 hours for this case, and average speed is 45 miles per hour. We get the same answer by plugging x = 40 into the final answer, so it checks out at least for this case.\n\nNote that the correct answer will only be 45 mph if x = 40. Any other value of x will produce a different result, and we don't have any information given to us that will give us x, so the best we can do is test different values of x just to make sure our answers make some sort of sense.\n\nAlso note that the obvious answer that you get by averaging x and x + 10 to give you x + 5 is wrong in general (it turns out to be correct if x = 40, but we don't really know if this is the case). We can't just average speeds together unless we know that an equal amout of time was spent traveling at each of these speeds, and we don't. This is a very popular standardized test trap that most people will fall for.
823086
Yes, traffic cops use them to collect data on the average speeds of traffic at different times.  There's one on my way in from work on the midnight shift the speed limit is 30 and I usually try to go as fast as possible, 60-70mph just for fun.  But then again I am driving a squad car.
874378
If you mean air speed - it is measured in knots.\nIf you mean altitude it is measured in metres.\nIf you mean distance flown - kilometres
963172
average speed =total distance/total time\n1.\ntotal distance=2km\ntotal time=1/2hr\naverage speed =4km/hr\n2.\ntotal distance=360km\ntotal time=5hr\naverage speed =360/5=72km/hr\nthanks & good luck
995779
To all those who answered 90 mph - BE MORE CAREFUL!\n\nMath Teacher
739275
I'd say an average of 3-4mph, depending on terrain, fitness and weather.\n\nThat's basically the amount we'd cover walking our dog at a fairly average speed and this was a reasonably hilly, walking across fields and in all weathers.
518246
The average is usually reckoned to be about 3 miles an hour on the flat, less if going up hill. It's possible to walk significantly faster than 3 miles an hour, but only for short distances.
37529
Well if I am going 10 miles per hour, that is an instantaneous speed (it is a scalar).\n\nIf I am going 10 miles per hour north, that is an instanteanous velocity (it is a vector).\n\nIf I am changing my speed by 5 miles per hour per second, that is an acceleration. Without a direction, it is a scalar. Of course, I could specify a direction, and then it would be a vector, so 5 miles per hour per second north is a vector expression of acceleration. \n\nOne can have an instantaneous vector acceleration, or an instanteous scalar acceleration, or an average vector acceleration or an average scalar acceleration. \n\nOne can also have a change of acceleration, called a boost, which can also be a vector or a scalar, depending on whether it has a direction associated with it or not. \n\nSo 2 miles per second cubed is a boost (scalar boost that is). If it as at some instant of time, it is instantaneous. If it is some integral over some time period, it is an average. And so on.
876839
speed is velocity - both measured as the change of distance divided by the change in time. You may mean the angular velocity, how fast is it spinning; or how fast the air is moving around the center (relative to the air not spinning); or how fast the tornado is moving across the ground.
761829
I would think speeding.
30694
20m/s.\nbecause the total time is 5s. and by defn of average speed it is the ratio of total distance travelled to total time taken i.e 100/5 = 20m/s
994628
53.3 km/hr\n\ntrip takes 1.5 hours so 80/1.5 gives you km/h.
356341
The Earth moves at an average speed of 107,218 kilometers/hour (66,625.2652 miles/hour) around the sun.  Additionally the Earth spins on its axis at about 165 mph.
273335
70 is probably about average.  I always heard it was ideal to get it to around 60 per minute.
835727
I would say occasional speeder. I might be speeding, but I'm staying with the flow of traffic (or on a completely empty road...it's easy to get a lead foot then. Nothing to compare yourself to) but, I am never weaving through traffic.
918850
If initial speed is V0 and the speed after a time t second is V,\n\nAcceleration is change in speed per unit time.\n\nAcceleration a = (V - VO) / t.\n\nThe average speed during this time t is \n\nV (average) = (V + V0) / 2.\n\nNote; if any quantity is changing uniformly, the average is found by adding the initial and final value and dividing the sum by 2.\n\nThe average speed can also be determined by dividing the total distance by total time of travel.\n \nV (average) = S / t.\n\nTherefore S/t = (V + V0) / 2.\n\nS = (V + V0)* t / 2.\n\nFrom a = (V - V0) / t we have V = V0 +at.\n \nTherefore S = {V0 +at + VO} * t /2 \n--------------- = {2 V0 t + at t } /2\n\n-------------- S = V0t + 0.5 a tt