1. Uniform Circular Motion and Gravity
October 3

2. 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

4. 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

5. 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

6. 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

7. 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

8. 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