This is the term for circular motion around an external axis.
What is revolving.
100
Linear motion is caused by force, in the same way that rotational motion is caused by ________
What is torque.
100
This is the tendency of an object to resist a change in its rotational speed.
What is rotational inertia.
100
Newton discovered that both the moon and falling apples are subject to ___________.
What is Earth's gravity.
100
This is the term for a projectile that falls continually around another object rather than into it.
What is a satellite.
200
This is the term for a line which touches a circle at only one point, and makes a 90 degree angle with the radius at that point.
What is a tangent line.
200
This is the average position of all the material making up an object.
What is the center of mass.
200
A figure skater can speed up or slow down during a spin by adjusting their _________ of ________.
What is moment of inertia.
200
This is the tangential speed of an object orbiting Earth close to the surface in a circular orbit.
8 km/s.
200
Math Question: How much time does it take an object to fall 5 m from rest?
What is one second.
300
This is the term for forces which point out from the center of a circle.
What are centrifugal forces.
300
Math Question: A boy with mass of 80 kg sits on a see-saw 1.25 meters from the fulcrum. Where should his 50 kg brother sit in order to balance him out?
2m from the fulcrum, on the other side.
300
A figure skater can adjust their speed up or down, but this quantity is conserved, and so remains constant.
What is angular momentum.
300
If the distance between two masses increases by 3 times, the force of gravity between them will decrease by how much?
By nine times, or 1/9
300
Orbits all follow this shape.
What is an ellipse.
400
Math Question: An object revolves about an axis 30 times per minute. What is the angular frequency in radians per second?
What is pi radians per second.
400
In order to cause an object to topple over, the center of mass needs to be moved beyond the _____________.
What is the support base.
400
Math Question: Which has more rotational inertia:
a.) A solid metal sphere with mass 5 kg and radius 10 cm, rotating on its axis.
or
b.) A solid metal cylinder with mass 5 kg and radius 10 cm, rotating on its long axis.
B
400
Math Question: What is the force of gravity between a 2 kg mass and the Earth?
19.6 or 20 N
400
This is the point on an orbit where the object has the most potential energy.
What is the apogee.
500
Math Question: What is the tangential speed of an object revolving about an axis 5 times per second at a distance of 0.75 meters?
What is 7.5 pi or 23.56 m/s
500
Where is the center of gravity of the solar system located?
Within the sun, slightly offset from the center.
500
Double Bonus Math Question: A 0.5 kg ball is spun around in a circle on a string. The string is 1 meter long and the ball is going around at a linear speed of 7 m/s
What would the ball's tangential speed be if, keeping everything else constant, the length of the string was shortened to 0.7 meters?
10 m/s
500
Black holes are unusual because light that falls past the ______ __________ cannot escape again.
What is the event horizon.
500
Math Question: A certain (unrealistic) planet orbits 5 meters away from its star and takes 3 days to complete an orbit. If another planet is orbiting 15 meters away, how long does its orbit take?