Question

I went from my house to the playground 300m away in 10 minutes then , I ran back and reached my house in 2 minutes . What was my average speed in m/s?

Answer 1

Going from house to playground, time taken = 10 mins = 10 x 60 = 600 seconds

Distance = 300 m

Speed = Distance/time = 300/600 = 1/2 m/s

Going from playground to house, time taken = 2 mins = 2 x 60 = 120 seconds

Distance = 300/120 = 5/2 m/s

Average speed = 2*S1*S2 / S1+S2

= (2 * 1/2 * 5/2) / (1/2 + 5/2)

= (5/2) / (6/2)

= 5/6 m/s

Answer 2

average speed =totaldistance travelled/total time taken

⇒totaldistance travelled=300*2= 600 m

⇒10min=60*10 sec=600sec

⇒2min= 60*2  sec=120sec

⇒tota time taken =600sec +120 sec =720sec

⇒average speed =600/720m/sec

⇒average speed=0.83m/sec ans

if you calculate in min

⇒totaldistance travelled=300*2= 600 m

⇒tota time taken =12 mins

average speed =totaldistance travelled/total time taken

⇒600/12 =50 m/ mins ans