Question

Gaurav is running with a speed of 15 km/hr. How much distance will he cover in two hours, in half an hour, in 10 minutes and in 10 seconds ?

Answer 1

Answer:

Two hours = 30km

half hour = 7.5 km

10 minutes = 2.5 km

10 seconds = 0.0416666... km

Explanation:

Given:

Gaurav's speed = 15 km/hr

To find:

Distance covered in :

• 2 hours
• $\frac{1}{2}$ hour
• 10 minutes
• 10 seconds

For finding distance covered in 10 minutes and 10 seconds , we need to convert the speed into m/s.

Distance in 2 hrs:

Distance = speed×time

Distance = 15×2

Distance = 30km

Distance in $\frac{1}{2}$ hour:

Distance = speed×time

Distance = $15 \times \frac{1}{2}$

Distance = 7.5 km

Distance in 10 min:

speed = 15 km/hr

15 km/hr = 15×$\frac{5}{18}$ = $\frac{75}{18} m/s$

Distance = speed × time

Time = 600 seconds ( 1 minute = 60 seconds)

Distance = $\frac{75}{18} \times 600 =2500metres = 2.5km$

Distance = 2.5km

Distance in 10 seconds:

Speed = $\frac{75}{18} m/s$

time = 10 seconds

Distance = 41.6666.....metres = 0.0416666666... km

Distance = 0.04166666..... km

Answer 2

$\rule{300}{2}$

GIVEN :-

Gaurav is running with a speed of 15 km/h.

$\\\longrightarrow$ Speed of Gaurav = 15 km/h

TO FIND :-

The distance travelled by Gaurav when the time is :

• 2 hrs
• 1/2 hr
• 10 mins
• 10 secs

$\\\longrightarrow$ The speed remains constant.(According to the question)

FORMULA TO BE USED :-

Distance = Speed × Time

SOLUTION :-

(i) When the time = 2 hrs

Speed = 15 km/h

Distance = 2 × 15

⇒Distance = 30 km

(ii) When the time = 1 hr

Speed = 15 km/h

Distance = 1 × 15

⇒Distance = 15 km

(iii) When the time = 1/2 hr

Speed = 15 km/h

Distance = 1/2 × 15

⇒Distance = 7.5 km

(iv) When the time = 10 mins

Time = 10/60 hrs = 1/6 hrs                 (∴ 1 hr = 60 mins)

Speed = 15 km/h

Distance = 1/6 × 15

⇒Distance = 2.5 km

(iii) When the time = 10 s

Time = 10/3600 hrs = 1/360 hrs        (∴ 1 hr = 3600 secs)

Speed = 15 km/h

Distance = 1/360 × 15

⇒Distance = 0.041666 km = 41.666 m

$\rule{300}{2}$