Question

A car moves with a speed of 40 km/h for 5 minutes and then with a speed of 60 km/h for the next 5 minutes. The total distance covered by the car is

Answer 1

Given :-

◉ A car moves with a speed s₁ = 40 km/h for time t₁ = 5 minutes and then with a speed of s₂ = 60 km/h for the same time t₁ = 5 minutes.

To Find :-

◉ Total distance covered.

Solution :-

The units of time and speed is not the same.(Speed is in hour and time in minutes)

So, We should either change speed in km/min or minute into hour. It's better for us to convert time into minute instead to avoid more calculations.

So, We know

⇒ 1 hour = 60 minutes

∴ 5 minute = 1/12 hour

Now, There are two situations during which the car moves with speed 40 km/h and 60 km/h respectively. Therefore, Total distance travelled is the sum of the distances covered in both the cases.

Case 1

In this case, We have

• Speed of car = 40 km/h
• Time taken = 1/12 hour

Distance travelled can be calculated as,

⇒ Distance = Speed × Time

⇒ Distance = 40 × 1/12

⇒ Distance = 10/3 km ...(1)

Case 2

We have,

• Speed of car = 60 km/h
• Time taken = 1/12

Similarly, Distance can be calculated as,

⇒ Distance = Speed × Time

⇒ Distance = 60 × 1/12

⇒ Distance = 5 km ...(2)

As discussed above,

⇒ Distance travelled = (1) + (2)

⇒ Distance travelled = 10/3 + 5

⇒ Distance travelled = 25/3

⇒ Distance travelled = 8.33 Km

Hence, The total distance travelled by the car is 8.33 Km.

Answer 2

Cᴏʀʀᴇᴄᴛ Qᴜᴇsᴛɪᴏɴ :-

• A car moves with a speed of 40 km/h for 5 minutes and then with a speed of 60 km/h for the next 5 minutes. The total distance covered by the car is

Gɪᴠᴇɴ :-

• Speed of the car in first 5 minutes = 40 km/hr.

• Speed of the car in next 5 minutes = 60 km/hr.

Tᴏ Fɪɴᴅ :-

• The total distance covered by the car.

Sᴏʟᴜᴛɪᴏɴ :-

• Speed of the car in first 5 mins = 40 km/hr.

${\boxed{{\bf{Distance\:Covered = Speed × Time\: Taken }}}}$

$\sf\large\purple{⇝60 \: mins = 1 \: hour}$

$\sf\large\purple{⇝5\: mins = \frac{1}{2} hr}$

$\sf\large\purple{☞ Distance \: covered \: = 40 \times \frac{1}{2} = 10/3 \: km}$

• Speed of the car in next 5 mins = 60 km/hr.

$\sf\large\purple{☞ Distance \: covered \: = 60\times \frac{1}{2} = 5 \: km}$

• Total distance travelled :-

$\sf\large\green{☞Total \: distance \: covered \: = 10/3 + 5km = 25/3 \: km}$

$\sf\large\green{☞Total \: distance \: covered \: = 8.33 \: km}$

${\boxed{{\bf{∴The\:total\:distance\:covered \:by\:car = 8.33 \:km.}}}}$