Question

a body moves with a velocity of 15m/s for 3 seconds and then travels with a velocity of 30m/s for 9 seconds . find average velocity

Answer 1

Explanation:

• Average velocity= total distance/total time taken
• i.e, Vavg= S1+S2+S3+..../t1+t2+t3+...

we can write like this,

• Vavg=V1t1+V2t2/t1+t2

(since v=s/t

s=vt)

therefore,

• Vavg=(15×3)+(30×9)/9+3
• Vavg=26.25 m/s

hope this helps...!!!

Answer 2

Initial velocity  u=30i^

Final velocity   v=40j^

Change in velocity  Δv=40j^−30i^

Magnitude    ∣Δv∣=302+402=50

Average acceleration   a=Δt∣Δv∣=1050=5 m/s2

Hope this method helps.