Can you help me with my physics subject?

Question

1. a pendulum is mounted in an elevator that accelerates upward with constant acceleration. Does the period increase, decrease, or remain the same? Explain..

2. The frequency with which the dog pant is the natural frequency of their respiratory system. why do they choose this frequency?

Answer 1

remember that the period of a pendulum is related to sqrt[L/g] where L is the length of the pendulum and g is the accel due to gravity

if the pendulum is in an upwardly accelerating elevator, then the "Effective gravity" on the pendulum is g+a, so the period becomes proportional to sqrt[L/(g+a)] and therefore becomes smaller

re the dog, i can only guess that panting at this frequency creates a resonance that minimizes the energy used by the dog in panting