PY 131 Chapter 3: Linear Motion

What is a point particle?

A point particle has no size, so it does not rotate

What is a reference frame?

A reference frame is necessary to say where an object is in space. We pick some point in space and call it The Origin.

What are the Cartesian coordinates?

The Cartesian coordinates are x, y, and z.

What is position?

Position is a vector quantity that describes the location of an object in space.

How is position different from distance?

Position is the vector that points from the origin to where the object is, whereas distance is just the length of that vector.

What is average speed?

Average speed is the distance moved divided by the time interval.

What is average velocity?

Average velocity is the displacement divided by the time interval.

What is instantaneous velocity?

Instantaneous velocity is the velocity at a given instant in time.

What is relative motion?

The speed and motion of an object are relative to the origin of the reference frame.

What is acceleration?

Acceleration is the rate of change of velocity.

What is the acceleration due to gravity?

The acceleration due to gravity is the acceleration at which all objects fall in the absence of air resistance.

What is the symbol for the acceleration due to gravity?

The symbol for the acceleration due to gravity is "g".

What is the value of g?

The value of g is approximately 9.81 m/s².

What is gravimetry?

Gravimetry is the measurement of the acceleration due to gravity.

What is the direction of the acceleration due to gravity?

The acceleration due to gravity points downwards, towards the center of the Earth.

What is the difference between average speed and average velocity?

Average speed is a scalar quantity, whereas average velocity is a vector quantity.

Can an object have a velocity of zero and an acceleration that is not zero at the same time?

Yes, an object can have a velocity of zero and an acceleration that is not zero at the same time.

If the velocity of object A is greater than the velocity of object B, does that mean the acceleration of A is greater than that of B?

No, not necessarily.

What is the acceleration formula?

The average acceleration is the change in velocity divided by the time interval.

What is the value used for g in the notes?

The value used for g in the notes is 10 m/s².

What is the variation in g due to?

The variation in g is due to the composition of the local rocks and the shape of the Earth.

What did Galileo discover about falling objects?

Galileo discovered that, in the absence of air resistance, all objects fall with the same acceleration.

What is displacement?

Displacement is the change in an object's position from its initial position to its final position.

What is the difference between instantaneous velocity and average velocity?

Instantaneous velocity is the velocity at a given instant in time, whereas average velocity is the displacement divided by the time interval.

What is the instantaneous acceleration?

The instantaneous acceleration is the acceleration at a given instant in time.