- #1

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## Homework Statement

A body travels 200 cm, in the first 2 sec,and 220 cm in the next 4 sec What will be the velocity at the end of seventh second from the start ?

## Homework Equations

##v_{avg}=\frac {Δx} {Δt}##

**3. The attempt at a solutio**

##(v_{avg})_1=\frac {Δx} {Δt}## for first 2 sec is 2m/2s which its 1m/s

##(v_{avg})_2=\frac {Δx} {Δt}## for next 4 sec which its 2.2m/4s=0.55m/s

So if we assume the body moved from t=6 to t=7 with speed 0.55m/s we get

##(v_{avg})_{tot}=\frac {Δx} {Δt}##

which its Δx=(0.55m/s.5m)+(1m/s.2s)=4.75m

Δt=7s

so the answer is Δx/Δt=4.75m/7s=0.67m/s=67cm/s

the answer says 10cm/s

I don't know where I did go wrong thanks