Which is not expecting acceleration?
A point on the outside of a spinning top whose rotational speed is constant.
A skydiver whose air resistance is equal to that of her weight.
A car on the freeway experiencing a net force of -120 N.
A submerged beach ball whose buoyant force is eight times the force of gravity on it.
Which is not considered to be a contact force?
Gravity(my choice)
Spring
Normal
Tension
Which is the definition of inertia?
The tendency an object has to accelerate.
A quanitive measurement of mass.
The tendency of an object’s motion to remain the same(my choice)
A qualitive measurement of mass.
A skydiver whose air resistance is equal to that of her weight.
gravity
tendency of motion to remain constant
To determine which is not expecting acceleration:
- A point on the outside of a spinning top whose rotational speed is constant: This point is experiencing centripetal acceleration due to its circular motion.
- A skydiver whose air resistance is equal to that of her weight: The skydiver is in free fall, experiencing acceleration due to gravity.
- A car on the freeway experiencing a net force of -120 N: This car is experiencing a net force, which can cause acceleration according to Newton's second law (F = ma).
- A submerged beach ball whose buoyant force is eight times the force of gravity on it: The beach ball is experiencing buoyant force, which can cause upward acceleration.
Based on the considerations above, the point on the outside of a spinning top whose rotational speed is constant is the one that is not expecting acceleration, as it maintains a constant rotational speed.
Now, to determine which is not considered a contact force:
- Gravity: Gravity is not a contact force as it acts at a distance between objects.
- Spring: A spring is a contact force, as it requires physical contact to exert its force.
- Normal: A normal force is a contact force exerted by a surface to support an object, so it involves physical contact.
- Tension: Tension is a contact force that occurs when a rope, cable, or any similar object is pulled or stretched.
Therefore, the answer is gravity.
Lastly, to determine the definition of inertia:
- The tendency an object has to accelerate: This option describes how an object resists changes in its motion, which is inertia.
- A quantitative measurement of mass: This option describes mass itself but does not define inertia.
- The tendency of an object’s motion to remain the same: This option accurately defines inertia as the tendency of an object to maintain its state of motion (either rest or constant velocity) unless acted upon by an external force.
- A qualitative measurement of mass: This option does not accurately define inertia, as it refers to the qualitative aspect of mass rather than the concept of inertia itself.
Therefore, the correct definition of inertia is the tendency of an object's motion to remain the same.