What is 2456 rounded to 2 significant figures?
TL;DR2,5*10^3Full explanation follows. Your question deals with two separate errors of definition:1. ROUNDING OFFIf you round (2456) down to the nearest hundred (2400), we call it truncating the number.Just “rounding off” without any further requirements means up or down to the closest level you want to reach, so there is, in fact, no ambiguity.In this case, all numbers including 2450 and between 2450 and 2550 (but not including 2550) are rounded to 2500 when rounding to the nearest 100.2. SIGNIFICANT DIGITSThe numbers 2400, 2456 and 2500 all have 4 significant digits (or “figures”), they are all written with an accuracy of 1 unit.If you want to round off 2456 to 2 significant digits, you will need to write your answer with an accuracy of 100 units, but using only two figures. In this case you need to remove the two zeroes and keep just the 2 and the 5.This is done with scientific notation (which, unfortunately, I am not able to do correctly on my mobile phone now, without the ability to write superscripts in this editor, so I use the sign ^ to denote the exponent).So, the answer to your question is:2,5*10^3
A car starting from rest accelerates to 50.0 m/s in 5.00 seconds. How do you find the acceleration and the distance covered by the car?
The problem has an ill formed conditions. There nowere said about the a(t) dependence. It coud be a good case when it sounds like “A car starting from rest accelerates to 50.0 m/s uniformely”, f.e.So the minim distance is zero meters. That accords to the variant when the car stood at rest all the 5 seconds and accelerates in a last moment so as its speed reaches the 50 m/s value. Last a moment can be a very small but a finite span to prevent infinity acceleration to be needed but provides the almost zero distance covered.And the maximum distance is 250 m/s by the very similar reason. This is, car reaches 50 m/s during the very small time from begining a moment and is moving all the 5 seconds with the constant speed.
An airplane has a ground speed of 350 km/hr in the direction due west. If there is a wind blowing northwest at 40 km/hr, calculate the true air speed and heading of the airplane?
Hello my friend. Thanks for the A2A…Airspeed is the speed of the aircraft relative to the wind blowing around it.Ground speed is the speed of the aircraft relative to the ground.There will be higher ground speed and low true airspeed if there is a tailwind. There will be low ground speed and higher airspeed is a headwind.Now, Ground speed = True Airspeed + Windspeed. So,True Airspeed = Ground speed — Wind speed.Aeronautical Calculations of Headwind and Crosswind.Here it is given that the aircraft is moving towards west. Therefore it is heading 270 degrees at a Groundspeed of 350 kmph.Now, the wind is blowing from Northwest.It means it is blowing from 315 degrees. The wind is blowing from NW to SE.So, the aircraft has both headwind component as well as cross wind components.So, angle between the wind and aircraft is therefore 315 — 270 = 45 degrees.It is to be remembered thatHeadwind = Windspeed * Cos (A).Crosswind = Windspeed * Sin (A).So, here, the headwind will beHW = 40 * Cos 45 = 40 * 0.707 = 28.28 km/h.CW = 40 * Sin 45 = 40* 0.707 =28.28 km/h.True Airspeed (TAS) =350 — ( — 28.28) = 350+28.28 = 378.28 km/h.Windspeed will be negative as it is a headwind. It will be positive as it is a tailwind.Due to the 45 degrees of cross wind, the track of the airplane will change to the below calculated Drift Angle.Drift Angle = (Windspeed * Angle between aircraft & wind) / True Airspeed.Drift angle = (40 *45)/378.28 = 4.75 degrees towards the Wind.So, the drift angle will be also 4.75 degrees.So, the new heading of the aircraft will be 274.75 degrees (West north-West); the true airspeed of the aircraft will be 378.28 km/h.See that the groundspeed is less than the true airspeed. So, it is headwind.Hope you got your answer. Thanks a lot..
What is the smallest 5-digit number?
Will 00000 work?Wait, that can be simplified, and is the same as simply 0. That means that the leftmost didgit must be superior to 0, as numbers can be shortened from the left. Smallest number that is superior to 0 is 1. The rest doesn’t matter.So the smallest 5-digit number is 10000.Edit: If your number can be negative (have a minus in front of it), you could try the biggest 5-digit number and put a minus in front of it, getting -99999.
Why has the speed of airliners remained more or less a constant over the years? Can we expect to fly from Toronto to Melbourne in an hour by 2050?
TL;DR We don't have faster planes because people can't afford to ride in them. Yes we could build planes that fly much faster, but there are good reasons we don't:Super-sonic flight is not permitted over most countries (including the US) because of the "sonic boom" that is created by the aircraft. That's why the Concorde flew routes mostly over oceans (i.e. New York to London), but not routes mostly over land (i.e. New York to Los Angeles).Wind resistance (aka aerodynamic drag) increases exponentially as an aircraft's speed increases. The amount of fuel required to reach and maintain high speeds also increases exponentially. Fuel is the single largest operating cost for most airlines. It's more than 50% of all operating costs. Most of your ticket price is paying for the jet fuel.The amount of time that could be saved on an average flight is extremely low, but the difference in cost would be several times the current ticket prices. Very few people are willing (or able) to pay that much money to save a an hour or two of time. Would you?A Boeing 777 cruises at Mach 0.85, and the Concorde cruised at Mach 2. From NY to London that translates to saving 4 hours of flight time, but most of the daily flights on earth are US domestic flights; they're a lot shorter.From NY to LA (one of the longer US domestic routes) the total time saved by using super sonic flights would be less than 2:45 (on a ~5:00 flight). Most routes would save significantly less time. How much is 1-2 hr of your time worth? Because for the price you'd pay for an economy seat on super-sonic flight you could probably charter a private jet and fly in style.Most flyers book flights with stops and lay-overs because those routes are cheaper. Relatively few flyers are even willing to pay a 10%-50% premium for a direct flight, and that saves them time and the significant inconvenience of changing planes!