Physics: Rotational, Projectile, Satellite Motion, Gravity

Half way to the center of a completely hollow planet with a thin uniform shell, your weight there compared to your weight on the outer surface would be...

ZERO.

If the earth rotated SLOWER about its axis, your apparent weight would...

INCREASE.

A space habitat is designed so that the variation in g between a person's head and feet is less than 0.01 g. If the person is 2m tall, then the min. radius of the habitat is...

200 m.

Toss a baseball bat into the air and it wobbles about its...

CENTER OF MASS!

Th force of gravity does work on a satellite when it is in...

ELLIPTICAL orbit.

A vertically-oriented rocket that is somehow able to maintain a continuous upward velocity of 8 km/s will...

ESCAPE from the Earth!

The concept of FORCE is not fundamental to...

Einstein's Theory of Gravitation

Since each rolling wheel of a railroad train is tapered, the narrow part of the wheel has a tangential speed that is...

SMALLER than that of the wide part.

A flywheel's diameter is twice that of another of the same shape & mass. The larger flywheel's rotational inertia is...

TWO times the other's.

A hunter on level ground fires a bullet at an angle of 2 degrees below the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?

The FIRED one.

The reason the moon does not crash into the Earth is that the...

moon has a sufficient TANGENTIAL SPEED.

A carnival has a Ferris wheel where the seats are located halfway between the center & the outside rim. Compared with a Ferris wheel with seats on are the outside rim, your ANGULAR speed while riding on this Ferris wheel would be...

the SAME and your TANGENTIAL SPEED less.

Angular Momentum

~ Angular Momentum = (mass)(velocity)(radius) ~ "Inertia of rotation" of rotating objects ~ AM = (rotational inertia)(rotational velocity)

Conservation of Angular Momentum

~ I = rotational inertia ~ w = rotational velocity ~ BIG I, small w => weights extended out, rotate slower ~ small I, BIG W => weights pulled in, rotate faster!

Tangential Speed

~ The speed of something moving along a CIRCULAR path. (direction of motion is always TANGENT to the circle!) ~ DIRECTLY PROPORTIONAL to Rotational Speed (@ a fixed radial distance)

Rotational Speed

~ aka: Angular Speed ~ Refers to the # of ROTATIONS/revolutions per min.

Torque

~ the ROTATIONAL counterpart of Force ~ If you want to make a stationary object rotate, apply Torque! ~ Equals: Lever Arm x Force