Question

You are driving home from school steadily at 95 km/h for 180km. It then begins to rain and you slow to 65 km/h. You arrive home after driving 4.5 h. (a) How far is your hometown from school? (b) What was your average speed?

Answer 1

Step-by-step explanation:

Given

Person travel 180 km with
`v_1=95\ km/h`

and slow down to
`v_2=65\ km/h` due to rain

time taken to cover 180 km is

`t_1=(180)/(95)`

`t_1=1.89\ hr`

total time
`T=4.5\ hr`

suppose
`t_2` is the time for which it travels with
`v_2=65\ km/h`

`t_2=T-t_1`

`t_2=4.5-1.89`

`t_2=2.61\ hr`

so distance travel during this time
`d_2=v_2* t_2`

`d_2=65* 2.61`

`d_2=169.65\ km`

total distance
`d=180+d_2`

`d=180+169.65`

`d=349.65\ km`

(b)Average speed

`v_(avg)=(Distance)/(time)`

`v_(avg)=(349.65)/(4.5)`

`v_(avg)=77.7\ km/h`