KNR 282 Exam 2 Questions

Motion

an objects change in position from one point to another

two things necessary for motion

space and time

Three classifications of movements

linear, angular and general (both linear and angular)

Linear Kinematics

Position, Speed, Velocity And Acceleration

Position

Distance travled, displacement

Speed

No Direction (Scalar quantity)

- Average Speed

-Instantaneous Speed

Velocity

Rate of change with reference (Vector)

- Average velocity

Instantaneous velocity

Acceleration

Rate of change with time

- Average acceleration

- Instantaneous acceleration

Distance

Measure of length of the path followed by the object

Displacement

- Straight-line distance in a specific direction from start point to finish

- Vector (Magnitude and direction)- arrowhead for direction and length

Acceleration

Rate of change in velocity

Acceleration is...

- A Vector (Magnitude and direction)

- If the magnitude or direction of the objects velocity changes then the object is accelerating

Acceleration Occurs when an object...

-Speeds up

- Slows down

- Starts

- Stops

- Changes direction

Newtons 1st Law Of Interia

- An object at rest will remain at rest unless acted on by an unbalanced force.

- An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force

Linear Momentum

product of mass and linear velocity

- The faster an object, the more momentum it has

- The larger the objects mass the more momentum it as

Momentum is...

A Vector

- The total moment of a system object is content if the net external force acting on it is 0

In a race the winner will have the fastest _________

Speed or velocity

In a perfect elastic collision, momentum is _______ and objects in collision _________

Conserved, Bounce off each other

What are the two types of collisions?

Inelastic, Elastic

elastic collision

Bounce off each other

- COR is closer to 1

Inelastic collision

Objects move together

- COR is closer to 0

What is the coefficient of Restitution?

To describe "elasticity" of a collision

Coefficient of Restitution is defined as

The absolute value of the ratio of the velocity of separation to the velocity of the approach

Velocity of separation

Difference between the velocities of the two colliding objects just after the collision

Velocity of approach

Difference between the velocities of the two colliding objects just before the collision

Newtons 2nd law of Motion (Law Of Acceleration)

The change of motion is proportional to the force impressed and takes place along the straight line in which that force is impressed"

Is it easier to accelerate something horizontally or vertically?

Horizontally

In a race what will the winner always have?

The Fastest Average speed

Newtons Laws

1- Interia

2- Acceleration

3- Action/Reaction

Velocity, and Acceleration arrows, both to positive pointed to the right

Speeding up

Velocity and Acceleration arrows, both negative pointing to the left

Speeding up

Velocity arrow to the right that's positive, and Acceleration to the left that is negative.

Speeding Down

Velocity to the left that is negative, and Acceleration to the right that is positive

Speeding down

Velocity arrow to the right that is positive, and acceleration =0

No Change

Velocity to the left that is negative, and acceleration is 0

No Change

How do we Convert Km/H To M/S?

Divide Km by 3.6

Apex Or highest Point velocity is?

0

Gravity Acting on Projectile is always?

-10

Acceleration and Velocity are considered?

Vectors

How do I Convert kilometers to Meters

Multiply by 1000

If an unbalanced horizontal force is applied to a body that is at rest, the body will:

Accelerate

When a sprinter uses starting blocks to enhance running performance, which of Newton's laws best represents the interaction of the sprinter and the blocks?

3rd Action-reaction

Which category of motion encompasses most human motions?

General

The larger and faster an object is the more ___ it has?

Momentum

Impulse-momentum relationship

impulse is equal to the change in the momentum of the object that the impulse acts on.