# An Object starting from rest travels 20 m in first 2 sec and 160 m in next 4 sec. What will be the velocity after 7 sec from the start?

1
by Ut8

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by Ut8

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t=2s

s=20m

v=s/t=20/2=10m/s

a=v-u/t=10-0/2=5m/s square

s=160m

t=4-2=2s

v=s/t=40m/s

u=10m/s

v=40m/s

a=v-u/t=15m/s square

t=7-2=5s

u=40m/s

v=?

a=v-u/t=40-x/5

125=40-x

v=85m/s

therefore final velocity is 85m/s