An airplane travels 2100km at a speed of 1000km/h, then encounters a headwind which slows it down to 800km for the next 1300km. What was the average speed of the plane for this trip? (3 marks)

Question

welshfella · Answer

average speed = total distance travelled / total time taken

welshfella · Answer

For the first part of the journey he work out the time   using  t1 = d / v.

welshfella · Answer

and do the same for the second part

first part  t1 = 2100/100  hours
2nd  part  t2 = 1300/800  hours

welshfella · Answer

so average speed =  (2100 + 1300) / (t1 + t2)

welshfella · Answer

* typo
first part = 2100 / 1000 hours