Uniform Circular Motion and Gravity October 3

You’re on a Ferris wheel moving in a vertical circle You’re on a Ferris wheel moving in a vertical circle. When the Ferris wheel is at rest, the normal force FN exerted by your seat is equal to your weight mg. How does FN change at the top of the Ferris wheel when you are in motion? FN remains equal to mg. FN is smaller than mg. FN is bigger than mg. None of the above 5 60

As a roller-coaster designer, what shape hill should you make so that the riders feel weightless during most of the ascent and decent of the hill? circular triangular parabolic It is not possible. 5 60

60 Which is stronger, the Earth’s pull on the Moon, or the Moon’s pull on the Earth? the Earth pulls harder on the Moon the Moon pulls harder on the Earth they pull on each other equally there is no force between the Earth and the Moon. it depends upon where the Moon is in its orbit at that time 5

60 If the distance to the Moon were doubled, then the force of attraction between the Earth and Moon would be: one quarter as big. one half as big. equal. two times bigger four times bigger 5

You weigh yourself on a scale inside an airplane that is flying with constant speed at an altitude of 20,000 feet. How does your measured weight in the airplane compare with your weight as measured on the surface of the Earth? 60 Greater than Less than same 5

The Moon does not crash into the Earth because: 60 It’s in Earth’s gravitational field The net force on it is zero It is beyond the main pull of Earth’s gravity It’s being pulled by the Sun as well as by the Earth none of the above 5