Question

A car travels half of the distance with constant velocity 30 m/s and the other half with constant velocity 50m/s. find the average speed of the car

Answer 1

Given :

➳ A car travels first half of the total distance at a speed of 30m/s and second half of the total distance at a speed of 50m/s.

To Find :

➛ Average speed of car.

SoluTion :

⇒ Average speed is defined as the ratio of total distance travelled to the total time taken. It is a scalar quantity having only magnitude.

⇒ SI unit : m/s

✭ When body covers first half of the total distance at a speed of $\tt{v_1}$ and second half of the total distance at a speed of $\tt{v_2}$, then average speed of body is given by

$\longrightarrow\tt\:v_{av}=\dfrac{2v_1v_2}{v_1+v_2}\\ \\ \longrightarrow\tt\:v_{av}=\dfrac{2(30)(50)}{30+50}\\ \\ \longrightarrow\tt\:v_{av}=\dfrac{3000}{80}\\ \\ \longrightarrow\underline{\boxed{\tt{v_{av}=37.5\:ms^{-1}}}}$

Answer 2

Answer:

Given:

• A car travels half of the distance with constant velocity 30 m/s and the other half with constant velocity 50m/s.

Find:

• Find the average speed of the car.

Using formula:

• Vav = 2(v1) (v2)/v1 + v2

Note:

• Vav => Average speed.
• v1 => Half of the distance speed.
• v2 => Second of the distance speed.

Calculations:

=> 2 (30) (50)/30 + 50

=> 3000/30 + 50

=> 3000/80

=> 37.5 ms-¹

Therefore, 37.5 ms-¹ is the average speed of the car.