A body initially at rest is accelerated at a rate of \(0.2 \mathrm{~ms}^{-2}\) for \(5 \mathrm{~s}\) under a constant force of \(50 \mathrm{~N}\). the work done on the body is ____________
Explanation
given: \(\mathrm{a}=0.2 \mathrm{~m} / \mathrm{s}^2, \mathrm{t}=5 \mathrm{~s}, \mathrm{f}=50 \mathrm{~N}\)
required \(\mathrm{W}=\) ?
correlating equation
\(\mathrm{W}=\mathrm{F} \times \mathrm{s}\)
Where \(\mathrm{s}=u \mathrm{t}+1 / 2 \mathrm{at}^2\)
since the body was initially at rest,
\(u=0\)
\(\mathrm{s}=0 \times \mathrm{t}+1 / 2 \mathrm{at}^2\)
\(s=1 / 2 \mathrm{at}^2\)
\(\mathrm{s}=1 / 2 \times(0.2) \times 5^2\)
\(=0.1 \times 25=2.5 \mathrm{~m}\)
\(\mathrm{W}=50 \times 2.5=125 \mathrm{~J}\)
