Question

A car travels at a rate of 30km/hr for 5 min and then at 40km/hr for 10 min
1) find the total distance travelled by the car
2) average speed of the car ​

Answer 1

Answer:

1) Case 1

d= v×t

= 30×5

=150

Case 2

d=v×t

=40×10

=400

Total Distance = 150+400=550

2)Total Distance = 550

Total Time=15

s=D ÷ T

=550÷ 15

=36.6666

Answer 2

Given :

• Speed of the car ( S₁) = 30 km / hr
• Speed of the car (S₂) = 40 km / hr

• Time taken (t₁) = 5 min = 0.08 hr
• Time taken (t₂) = 10 min = 0.16 hr

To find :

• Total distance traveled by the car
• Average speed of the car

Solution :

we know that ,

$\implies \mathtt{S = d / t }$

here ,

• S = speed
• d = distance
• t = time

Hence,

→ S₁ = d₁ / t ₁

→ d₁ = S₁ x t ₁

→ d₁ = 30 x 0.083

→ d₁ = 2.49 km

Similarly ,

→ S₂ = d₂ / t ₂

→ d₂ = S₂ x t ₂

→ d₂ = 40 x 0.16

→ d ₂= 6.4  km

Total distance covered (D)

→ D = d₁ + d₂

→ D = 2.49 + 6.4

→ D = 8.89 km

Average speed is given by the formula ,

→ Average speed = Total distance / Total time

→ Average speed = D / t₁ + t₂

→ Average speed =  8.89 / 0.083 + 0.16

→ Average speed = 8.89 / 0.243

→ Average speed = 36.58 km / hr

The average speed of the car is 36.58 km / hr .