Towns A and B in the figure below are 80.0 km apart.?
Towns A and B in the figure below are 80.0 km apart. A couple arranges to drive from town A and meet a couple driving from town B at the lake, L. The two couples leave simultaneously and drive for 2.50 h in the directions shown. Car 1 has a speed of 90.0 km/h. If the cars arrive simultaneously at the lake, what is the speed of car 2? 230 km/h Incorrect: Your answer is incorrect. Your response differs from the correct answer by more than 100%. Picture: http://www.webassign.net/sf/p3_47.gif Work: Car 1 I'll make from town A. At 90KPH for 2.5 hrs., car 1 travels 225km. Distance car 2 has to travel, 800 - 225 = 575km. In 2.5 hrs, car 2 would have to be travelling at (575/2.5) = 230kph. Not sure what I'm doing wrong ... PLEASE HELP. Thanks a bunch.
A person goes 10 km north and 20 km east. What will be their displacement from the initial point?
Using the triangular law of vector addition.The displacement line is given by the hypotenuse which joins the start point and the end point.Hence hypotenuse is sqrt(N^2+E^2)=Sqrt(10^2+20^2) = 22.36 kmDirection of the displacement vector is given by atan(opposite/adjacent) = atan(10/20) = 26.56 degrees with respect to east measured anticlockwise.P.S: please avoid asking such silly questions. Let's make Quora a knowledge sharing platform (knowledge which matters and not thought in school)
An aeroplane flies 600 km in 20 minutes then the speed of aeroplane is?
Speed = distance/timeDistance = 600kmTime = 20 minsSpeed = 600km/20min = 30km/min (read as 30 killometer per min means, in 1 min the aeroplane will cover a distance of 30 km)To calculate speed in km/hourConvert time in hours1 hour = 60 minOr 1 min = 1hour/60Therefore 20 minutes = 20 * ( 1 hour /60)= 1 hour/3Speed (in km/hr) = 600km/ (1 hour/3)To bring the dividing term into multiplication, we take it's reciprocal and use multiply sign instead if divideMeansSpeed = 600km * 3/1 hour= 1800 km/hourOrEarlier we have a speed of 30km per minIn 1 min it will cover 30 kmIn an hour or 60 min it will cover a distance of = 30*60 km = 1800Again speed is 1800 km per hour (Ans)
A person during his journey travels 40 min at a speed of 30 km/h another 50 min at 60 km/hr and lastly travels 1 hr at a speed of 30 km/hr. What is his avg speed?
40/60 (of an hour) x 30 k/hr = 20 km50/60 x 60=50 km1 x 30 =30 kmadd those together and you went 100km40 min+50min+60min = 150 min = 150/60 hrvelocity = distance/time = 100/(150/60)= 100 x 60/150 =6000/150 = 40 km/hr