Question

A car moves with a speed of 80 km/h for 15 minutes and then with a speed of 60 km/h for next 15 minutes. The total distance covered by the is?

Answer 1

Answer:

Explanation:

Vavg= 2Vi Vf/Vi+Vf

Vavg= 2 × 80 × 60/ 80 + 60

Vavg = 9600/ 140

Vavg = 68 ms-1

Answer 2

Answer :-

35km

Explanation :-

Given :

A car takes 80km/hr for first 15min and 60km/hr for next 15min.

Convert 15 minuets into secomds,

=> 15/60hr

=> 0.25hr

To Find :

Total distance travelled by the car = ?

Solution :

We know,

$\boxed{\sf{}Distance=Time \times Speed}$

Distance travelled in first 0.25hr

$\implies \sf{}Distance=Time \times Speed$

$\implies \sf{} 0.25hr \times 80km/hr$

$\implies \sf{}\therefore 20km$

Distance travelled next first 0.25hr

$\implies \sf{}Distance=Time \times Speed$

$\implies \sf{} 0.25hr \times 60km/hr$

$\implies \sf{}\therefore 15km$

Total distance,

$\implies \sf{}d_1+d_2$

$\implies \sf{} (20 + 15)km$

$\sf{}\therefore 35km$

Therefore,total distance travelled by the car is 35km