URGENT: Have 2 questions I got 2 questions, if anyone can answer one or both of them, ill appreciate it. thanks! 8. Why is it difficult to measure the perihelion advance of the planet Venus? 9. You are in an elevator at the top of the CN tower. You have a pendulum and allow it to oscillate. The elevator falls to the ground after someone cuts its support cables. What does the pendulum do? Ignore the air resistance acting on the pendulum and the elevator.