A car covers one third of the distance with 20 kmph and the rest with 60 kmph.The average spped of the car is
Answers
Answered by
2
Let the total distance to cover = d km
one third of the distance is covered with 20 kmph
So d₁ = d/3
v₁ = 20 km/h
t₁ = d₁/v₁ = (d/3)/20 = d/(3*20) = d/60 hour
Rest distance, d₂ = 2d/3
v₂ = 60 kmph
t₂ = d₂/v₂ = (2d/3) / 60 = d/90 hour
total time,t = t₁ + t₂ = d/60 + d/90 = 5d/180 = d/36 hour
average speed = d/t = d/(d/36) = 36 km/h
one third of the distance is covered with 20 kmph
So d₁ = d/3
v₁ = 20 km/h
t₁ = d₁/v₁ = (d/3)/20 = d/(3*20) = d/60 hour
Rest distance, d₂ = 2d/3
v₂ = 60 kmph
t₂ = d₂/v₂ = (2d/3) / 60 = d/90 hour
total time,t = t₁ + t₂ = d/60 + d/90 = 5d/180 = d/36 hour
average speed = d/t = d/(d/36) = 36 km/h
Answered by
1
LET TOTAL DISTANCE = X km
X1 = X/3 km
V1 = 20 km/h
X2 = 2X/3 km
V2 = 60 km/h
SPEED = DISTANCE / TIME
TIME = DISTANCE / SPEED
t1 = X1 / V1 t1 = X / 60 h
t2 = X2 / V2 t2 = X / 90 h
TOTAL TIME,
t = t1 + t2
t = X / 60 + X / 90 = X / 36 h
AVERAGE SPEED = DISTANCE / TIME
= X / (X/36)
= 36 km/h
X1 = X/3 km
V1 = 20 km/h
X2 = 2X/3 km
V2 = 60 km/h
SPEED = DISTANCE / TIME
TIME = DISTANCE / SPEED
t1 = X1 / V1 t1 = X / 60 h
t2 = X2 / V2 t2 = X / 90 h
TOTAL TIME,
t = t1 + t2
t = X / 60 + X / 90 = X / 36 h
AVERAGE SPEED = DISTANCE / TIME
= X / (X/36)
= 36 km/h
Similar questions