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InterviewSolution
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In a shotput event an athlete throws the shotput of mass `10 kg`with an initial speed of `1 ms^(-1)` at `45^@` from a height `1.5 m` above ground. Assuming air resistance to be negligible and acceleration due to gravity to be `10 ms^(-2)`, the kinetic energy of the shotput when it just reaches the ground will beA. 2.5 JB. 5 JC. 52.5 JD. 155 J |
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Answer» Correct Answer - D (d) Given, h=15 m, `v=1ms^(-1), m=10 ms^(-2)` From conservation of mechanical energy, `(PE)_(i)+(KE)_(i)=(PE)_(f)+(KE)_(f)` `rArr " " mgh+(1)/(2)mv^(2)=0+(KE)_(f)` `rArr" "(KE)_(f)=mgh+(1)/(2)mv^(2)` `rArr" "(KE)_(f)=10xx10xx15+(1)/(2)xx10(1)^(2)` =150+5=155J |
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