You are driving home from school steadily at 100 km/h for 180 km . It then begins to rain and you slow 63 km/h instantly. You arrive home after driving 4.0 hours how far is your hometown from school

Distance between hometown and school is 318.6 km

Explanation:

Initially, the driving speed is 100 km/hr and the distance covered having this speed is 180 km.

The time taken to cover this distance is determine by the relation:

Here u is initial speed and s₁ is the distance covered.

Substitute 100 km/hr for u and 180 km for s₁ in the above equation.

t = 1.8 hr

Now, the speed is decreased to 63 km/hr due to rain.

Total time taken to reach home from school is 4 hours. But. 1.8 hrs is used to covered 180 km, so the remaining time is left to traveled the remaining distance to reach home.

Remaining time, t₁ = (4 - 1.8)hr = 2.2 hr

Distance covered in time 2.2 hr having speed 63 km/hr is:

s₂ = 63 x 2.2 = 138.6 km

The total distance between hometown and school is:  

s = s₁ + s₂ = 180 + 138.6

s = 318.6 km