Answer:
d. 41.4
Step-by-step explanation:
The initial diameter di = 100mm
The initial height hi {✓59m
Final height = 25 m
Final diameter = ?
Initial volume = after forging volume
D*(di)²*hi = D *(df)²*hf
D will cancel out from either sides of the equation
100² x 50 = df²x25
10000x2 = df²
20000 = df²
df = √20000
df = 141.42mm
Change in diameter = 141.42-100
= 41.42
The percentage change = 41.42/100*100
= 41.4%
The last option is the answer