Children are playing in a roundabout and they want to spin faster. Assume no external forces are applied, what could be done to make it rotate faster?

• Add more children at the edge of the roundabout.

• Have all of them sit instead of standing up.

• Have children with larger weights move to the center of the roundabout.

• Add more children to the center of the roundabout.

Where the center of gravity of a circle lies?

• At its centre

• Anywhere on its radius

• Anywhere on its circumference

• Anywhere on its diameter

What is one way you might increase the stability of an object?

• Lower the center of gravity

• Raise the center of gravity

• Increase the height of the object

• Shorten the base of the object

Tags

NGSS.HS-PS2-4

The property of a body to resist change in motion.

• mass
• weight
• volume
• inertia

Tags

NGSS.HS-PS2-1

A person sits on a freely spinning lab stool that has no friction in its axle. When this person extends her arms,

• her moment of inertia increases and her angular speed decreases.
• her moment of inertia decreases and her angular speed increases.
• her moment of inertia increases and her angular speed increases.
• her moment of inertia increases and her angular speed remains the same.

The center of gravity of the bolt in the picture is in the center of the bolt at the level of the arrow. As it sits on the desk, it is in a(n) ___________________________ position with respect to its center of gravity.

• neutral

• stable

• unstable

• irreversible

The center of gravity of the bolt in the picture is in the center of the bolt at the level of the arrow. As it sits on the desk, it is in a(n) ___________________________ position with respect to its center of gravity.

• neutral

• stable

• unstable

• irreversible

Why is the car on the left unstable?

• Its center of mass is high

• it has a narrow base

• it has a high height

• all of the above

What is the difference between Torque and force?

• Force is a linear quantity that causes linear motion, while torque is a rotational quantity that causes rotational motion.

• Torque is a linear quantity that causes linear motion, while force is a rotational quantity that causes rotational motion.

• Both torque and force are linear quantities that cause linear motion.

• Torque and force are the same and can be used interchangeably.

What is the distance the masses on the right of the fulcrum need to be to balance with the two masses on the left?

• .65 m
• .56 m
• .79 m
• .39 m

Tags

NGSS.HS-PS2-1