1. A paper pinwheel is spinning in the wind. Which statement is correct about the forces responsible for the rotation? The components of gravity and the force of wind that point through the pivot are responsible for the rotation.

Only the perpendicular component of wind is responsible for the rotation, because gravity points downward.

Only the perpendicular component of gravity is responsible for the rotation, because wind points toward the pivot. <- MY ANSWER

The perpendicular components of gravity and the force of wind are responsible for the rotation.

2. Which statement about kinetic and static friction is accurate?

Static friction is greater than kinetic friction, but they both act opposite the applied force.

Static friction is greater than kinetic friction, and they both act in conjunction with the applied force.

Kinetic friction is greater than static friction, but they both act opposite the applied force.

Kinetic friction is greater than static friction, and they both act in conjunction with the applied force.

3. A group of engineers is preparing a satellite to land by moving it 10% closer to Earth in each rotation. Which statement is correct about the rotational inertia of the satellite?

Rotational inertia decreases proportional to the decrease in the radius of rotation.

Rotational inertia increases proportional to the decrease in the radius of rotation. <- MY ANSWER

Rotational inertia first decreases and then increases as the satellite is ready to land.

Rotational inertia does not change because it is conserved.

4. In the experimental setup shown (see image attached), a car has one end of a string attached to it. The other end of the string has a hanger on which metal discs can be added or removed. The car moves along the table, and two photogate probes sense the motion of the car. The probes send information to a computer that displays the experimental results.
Which quantity is being held constant in this experiment?

mass
force
acceleration
velocity <- MY ANSWER