BSc Nursing GNM 2019 Solved Paper

Work done by the force
= Force × Displacement
or ‌‌W=F×s . . . (i)
But from Newton's second law,
we have
Force = Mass × Acceleration
i.e. ‌‌F=ma . . . (ii)
Hence, from Eqs. (i) and (ii), we get
W=mas=m(‌

d2s

dt2

)s‌‌...‌ (iii) ‌
‌‌‌‌∵a=‌

d2s

dt2

)
‌ Now, we have, ‌s=‌

1

3

t2
∴‌‌

d2s

dt2

‌‌=

d

dt

[

d

dt

(

1

3

t2)]
‌‌=

d

dt

×(

2

3

t)=

2

3

Hence, Eq. (iii) becomes
W=

2

3

ms=

2

3

m×

1

3

t2=

2

9

mt2
Given, m=3kg,t=2s
∴‌‌W=frac‌

2

9

×3×(2)2=frac‌

8

3

‌J