Question

If the car went 30 km west in 25 min. and then 40 km south in 35 min., what would be its average speed? 70 km/h 70. km/h 0.1 km/h 0.14 km/h

Answer 1

The car went 30 km west in 25 min. and then 40 km south in 35 min average speed of the car is 70.7 kmph.

Step-by-step explanation:

To find the average speed traveled by a person or thing when total distance traveled and total time taken is given firstly we need to check whether units of all given values be either in SI system or MKS system.

For example if the given values one value is in MKS and another value is in SI system we need to convert the values in either of the system.

The average speed is given by the formula:

`\text { Average speed }=\frac{\text { Total distance travelled }}{\text { Total time taken }}`

Given that, the car went 30 km west in 25 min. and then 40 km south in 35 min.

Convert time given into hours so that all values be in SI system divide the given value by 60.

For 25 minutes:

`\Rightarrow (25)/(60)=0.41 \text { hours }`

For 35 minutes:

`\Rightarrow (35)/(60)=0.58 \text { hours }`

Total distance travelled by car = car travelled 30 km west
`+` car travelled 40 km south = 70 km

Total time taken = car travelled 30 km west in 0.41 hours
`+` car travelled 40 km south in 0.58 hours = 0.99 hours.

Now,

`\Rightarrow \text {Average speed}=(70)/(0.99)`

`\therefore \text { Average speed }=70.7 \ \mathrm{kmph}`

Thus, from the above calculation we can say that the car average speed be 70.7 kmph.

Answer 2

70 km/h

Step-by-step explanation:

The formula for average speed is;

( total distance covered) / ( total time taken)

The total distance covered would be;

30 km + 40 km = 70 km

The total time taken is;

25 min + 35 min = 60 min = 1 hr

The average speed is thus;

70 km/1 hr = 70 km/h