Answers

2015-07-01T16:28:08+05:30
S=ut+1/2*a*t²
20=1/2*a*4
20=2a
a=10m/s²
In 7 seconds
a=(v-u)/t
10=v-0/7
70m/s=v
Velocity after 7 seconds is 70 m/s
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