The energy of bird flight as a function of body weight is given by, E = 429 w−0.35, where w is the weight of the bird (in g) and E is the brain weight (in cal/g/hr). Suppose that the weight of a bird weighing 10 g is increasing at a rate of 0.001 g/hr. Find the rate at which the energy expenditure is changing with respect to time in cal/g/hr/hr to four decimal places.

Step-by-step explanation:

Energy of bird flight is given by

Differentiating with respect to time we get

Now when

The rate at which the energy expenditure is changing with respect to time  is

(a) the volume of the cone is 20/3 in3

hence, option a is correct.

9 sandwiches per hour

step-by-step explanation:

when we have a rate, we want a 1 in the denominator

27/3 = 9

27 sandwiches/ 3 hours = 9 sandwiches/hour