Answer:
W = 21.44*10⁶J
Step-by-step explanation:
Given
y = x² (0 < x < 4)
γ = 10000 N/m³
W = ?
If we apply
y = 4² = 16 = h
y = x² ⇒ x = √y
then
V = π*(√y)²*dy = π*y*dy
W = (γ*V) *(16-y) = γ*π*y*dy*(16-y)
⇒ W = γ*π*∫y*(16-y)dy = γ*π*(8y²-(y³/3))
finally we obtain (0 < y < 16)
W = γ*π*(8y²-(y³/3)) = 10000*π*(8*16²-(16³/3)) = 21.44*10⁶J