General Physics MIDTERM 2 Chapters 7-11 Review (Conceptual and Review like Questions) (copy)

Linear Momentum

This is the product of an object’s mass and velocity (v) THEY ARE ALL VECTOR QUANTITIES! besides mass- the units are kg m/s

Impulse

the product of force acting on an object and the time where the force acts. (change in momentum)

The F_net MUST equal 0 if that is the case. (look at the equations)

How can the conservation of linear momentum be achieved?

The entire system of the momentum before and after!

What else is conserved in the conservation of linear momentum if the momentum for each individual mass will not be equal?

The heights for the elastic collision are the same so they can cancel each other out and the only factor we focus on is the KE of the masses

In elastic collisions, why is momentum conserved in both itself and total energy? (or mechanical energy)

Many inelastic collisions involve cars colliding or objects colliding which can result in damage and case the energy to be converted into heat.

In inelastic collisions, what is a possible reason to why momentum and energy is not conserved?

Center of Mass

This is the point where all the masses of an object can be considered concentrated

The center of gravity and the center of mass are the same.

What is a main characteristic in a horizontal mounted rod?

This is due to the pull of gravity being different for each part.

Why isn’t the center of mass and the center of gravity equivalent to each other in a vertically mounted rod?

Angular Displacement

This is the type of displacement that is done when an object or someone moves in circles- can be measured in radians, degrees, or revolutions, but preferably radians

We will only deal with the centripetal acceleration.

When an object is rotating at constant speed, what does that mean for the acceleration?

Tangential acceleration

When the object is constantly speeding up as it rotates, what is the acceleration that we will be focusing on?

Torque

The measure of effectiveness of a force in producing a rotation of an object, which is measured through the product of force and the perpendicular distance from the axis of rotation to the line along which the force acts.

The product of force and the perpendicular distance from the axis of rotation.

How can we measure the torque?

Not really.

In static equilibrium problems, whether the axis was positive or negative does it matter which one you set up?

Moment of Inertia

This is the tendency to resist rotational motion

This is due to the center of mass being different for each object.

Why is moment of inertia different for certain solids?

Smaller inertia

If we have a closer mass, what does that mean for the inertia.

Weights together due to having smaller inertia which increases the velocity.

According to the spinning stool experiment, will the velocity be greater when we have the weights together or far apart?

A sliding object would make it first due to having a larger KE since the rolling object has both translational and rolling KE.

When we compare a sliding object and rolling object, which one would make it first down the incline if they were released at the same time?

This is a conservative force

Spring force is a what type of force?

The equation would be negative because it is trying to restore the spring back to equilibrium.

Because spring force is a restoring force, what does that mean for the equation?

k

This is the measure of the amount of force that it takes to compress or expand a spring per linear meter- the stiffness of the spring.

x

This is the displacement from the equilbirium position or rest position

The system is not moving, and we can set up the forces depending on how the spring will move

In equilibrium, the spring is located without any external force doing anything, what can we assume about the system?

Amplitude

When a spring is oscillating, what is the distance between the equilibrium and the highest point of the spring when its either compressed or expanded? (can also be known as extreme ends)

The acceleration is at its maximum (means the v would be 0 at both ends)

When we reach the amplitude, what does that mean for the acceleration?

Its maximum (making the a=0)

When the spring is at equilibrium, what is the velocity at?

Density

This is a better way to describe fluids instead of mass with solid systems.

Pressure

Can be used to act on fluids instead of force itself.

Decreases

As area increases…. Pressure?

Buoyant Force

This is an upward force that an object exerts when it is partially or fully immersed in a fluid

The buoyant force is always equal to the weight if that is the scenario.

When an object is fully or partially submerged in water, does the buoyant force change?

There is a string attached to the object.

When an object has an apparent weight after being submerged in water, what does that mean about the object?

The velocity will increase (area decreases)

When we decrease (or reduce) the cross section of a hose, what does that mean for the velocity of the system?

When the fluid displaced at the point are at the same level.

In a U-tube, when are the pressures of the 2 sides equal to each other?

The pressure will be equal to each other at a different point.

Let’s say we have a U-tube, and we must on one side of the fluid, what does that mean to the pressure at a point?

Bernoulli’s Equation

This equation is used for systems that have a steady, non viscous flow.

The height changing tubes.

In Bernoulli’s Equation, what does the y normally stand for?

Car crashes, balls not bouncing back to its original height, or a ball of clay sticking to a wall.

What are some examples of inelastic collisions?

This is when KE and momentum are conserved, so when billiard balls are colliding and they go off with towards each other with equal speed.

What are some examples of elastic collisions?

This is where the pipe first enters.

Intel

This is the area where the fluids meet each other- also where the pressures are equivalent to each other.

Interface

Apparent Weight

This is the weight once an object is submerged in water when its either held by a spring or a string.

P₁ and P₂ is typically 0

When we are trying to find our maximum velocity OR we are told that our velocity will be at its max, what can we infer about P₁ and P₂?

Yes (they will be equal to each other)

When we talk about a perfectly elastic collision, is the total KE conserved?

No (majority of the time it will only be on the x-axis)

In a perfectly elastic collision, does the direction of the objects change?