Answer:
E. 800%
Step-by-step explanation:
Since,
u = 8d/h² __________ eqn (1)
Now, density (d) is doubled and usage (h) is halved.
Hence the new life (u'), becomes:
u' = 8(2d)/(0.5h)²
u' = 8(8d/h²)
using eqn (1), we get:
u' = 8u
In percentage,
u' = 800% of u
In words, the percentage increase in useful life of the equipment is 800%.
Answer: E. 800%
Step-by-step explanation:
The useful life of a certain piece of equipment is determined by the following formula: u =(8d)/h^2, where u is the useful life of the equipment, in years, d is the density of the underlying material, in g/cm3, and h is the number of hours of daily usage of the equipment.
Assuming d = 1 and h = 1, then
u = (8 × 1)/1^2 = 8
If the density of the underlying material is doubled and the daily usage of the equipment is halved, it means that
d = 2 and h = 1/2 = 0.5, therefore,
u = (8 × 2)/0.5^2 = 16/0.25 = 64
64/8 = 8
The percentage increase in the useful life of the equipment is
8 × 100 = 800%
