Problem 10.53

10.53. a)

Angular momentum is given by
$\vec{L} = \vec{r} \times \vec{p}$
$L = 2(5 m)(75 kg)(5 m/s) ~=~ 3750 kg \cdot m^{2}/s$

b)
$K_{1} = 2 \frac{1}{2} (75 kg)(5m/s)^{2}$
K₁ = 1.88 kJ

c)
Angular momentum in conserved, so therefore
$L = 3750 kg \cdot m^{2}/s$

d)
By conservation of angular momentum,
3750 = 2(2.5)(75)(v₂)
v₂ = 10.0 m/s

e) $K_{2} = 2 \frac{1}{2} (75 kg)(10 m/s)^{2}$
K₂ = 7.5 kJ

f)
W = K₂-K₁
W = -5.62 kJ