Question

A car covers 40 kilometers from 6:00 a.m. to to 7:00 a.m., 20 km from 7:00 a.m. to 8:00 a.m. and 30 kilometres from 8:00 a.m. to 9:00 a.m. Calculate the average speed of the car?

Answer 1

Solution :

⏭ Given:

✏ A car covers 40kms from 6 AM to 7 AM, next 20kms from 7 AM to 8 AM, and last 30kms from 8 AM to 9 AM.

⏭ To Find:

✏ Average speed of the car

⏭ Concept:

✏ Average speed is defind as ratio of total distance travelled to the total time.

⏭ Formula:

✏ Since time interval is same for all three cases.

✏ In this type of questions, Formula of average speed is given by...

$\star \: \underline{ \boxed{ \bold{ \sf{ \pink{ \large{V_{av} = \dfrac{Total \: distance}{Total \: time}}}}}}} \: \star$

⏭ Calculation:

$\mapsto \sf \: V_{av} = \dfrac{40 + 20 + 30}{3} \\ \\ \mapsto \sf \: V_{av} = \frac{90}{3} \\ \\ \mapsto \: \underline{ \boxed{ \bold{ \sf{ \purple{ \large{V_{av} = 30 \: kmph}}}}}} \: \gray{ \bigstar}$

⏭ Additional information:

• Average speed is scalar quantity.
• Average velocity is vector quantity.

Answer 2

Answer:

30 km/h

Explanation:

average speed= total distance/ total time

40km+20km+30km/3

= 90km/3= 30km/h