D is partly constant and partly varies with W,

Question

D=115 when W=1150 and D=625

Answer 1

To find the constant part of D, we can subtract the variable part of D from the total value of D when W is at its maximum value:

Constant part of D = D - Variable part of D
Constant part of D = 115 - 625
Constant part of D = -510

Therefore, the constant part of D is -510.

To find the variation of D with respect to W, we can subtract the constant part of D from the total value of D when W is at its maximum value:

Variable part of D = D - Constant part of D
Variable part of D = 625 - (-510)
Variable part of D = 625 + 510
Variable part of D = 1135

Therefore, the variable part of D is 1135.

So, we can say that D is partly constant (-510) and partly varies with W (1135).