Question

amirah runs at an average speed of 5 km/h for 1/5h before walking for 1/2h at a certain average speed. If she travels a total distance of 2km, calculate her average walking speed

Answer 1

Answer:

20/7

Step-by-step explanation:

Initial velocity = 5kmph

nitial velocity = 5kmphTime travelled with this velocity =1/5 h

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5= 1km

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5= 1kmTotal distance = 2 km

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5= 1kmTotal distance = 2 kmSo, remaining= 1 km

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5= 1kmTotal distance = 2 kmSo, remaining= 1 kmTime taken to travel this dis.= 1/2 h

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5= 1kmTotal distance = 2 kmSo, remaining= 1 kmTime taken to travel this dis.= 1/2 hTherefore, next velocity= 1÷1/2

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5= 1kmTotal distance = 2 kmSo, remaining= 1 kmTime taken to travel this dis.= 1/2 hTherefore, next velocity= 1÷1/2= 2kmph

nitial velocity = 5kmphTime travelled with this velocity =1/5 hTherefore, Distance = 5 x 1/5= 1kmTotal distance = 2 kmSo, remaining= 1 kmTime taken to travel this dis.= 1/2 hTherefore, next velocity= 1÷1/2= 2kmphFinally, avg. velocity = 2.v1.v2/v1+v2

= 20/7

20/7 kmph