Answer:
Vm = 128 km / h
Explanation:
The interview is at 11:15 am and he starts a trip at 8 am, the total time he has to arrive is -
ΔT = 3 hours and fifteen minutes = 3.25 hours
The total space he needs to cover is 300 km.
The time he spends on the first 100 kilometers -
V = ΔS / Δt
100 = 100 / Δt1
Δt1 = 1 hour
The time spent in the next 40 km
Vm = ΔS / Δt
40 = 40 / Δt2
Δt2 = 1 hour
The space he has already covered in two hours -
ΔS = 100 + 40 = 140 km
Make total time he has already spent 2 hours, left over -
Δt = 3.25 - 2
Δt = 1.25 hours
The space he needs to travel is missing -
ΔS = 300 - 140
ΔS = 160 km
The average speed he must maintain to get a time -
Vm = 160 / 1.25
Vm = 128 km / h
