imension 

2.6 Freely Falling Bodies  

2.6 Freely Falling Bodies  

In the absence of air resistance, it is found that all bodies at the
same location above the earth fall vertically with the same acceleration.

2.6 Freely Falling Bodies  

In the absence of air resistance, it is found that all bodies at the
same location above the earth fall vertically with the same acceleration.

Furthermore, if the distance of the fall is small compared to the
radius of the earth, the acceleration remains essentially constant throughout the fall.

2.6 Freely Falling Bodies  

In the absence of air resistance, it is found that all bodies at the
same location above the earth fall vertically with the same acceleration.

Furthermore, if the distance of the fall is small compared to the
radius of the earth, the acceleration remains essentially constant throughout the fall.

This idealized motion, in which air resistance is neglected and the
acceleration is nearly constant, is known as free-fall.

2.6 Freely Falling Bodies  

In the absence of air resistance, it is found that all bodies at the
same location above the earth fall vertically with the same acceleration.

Furthermore, if the distance of the fall is small compared to the
radius of the earth, the acceleration remains essentially constant throughout the fall.

This idealized motion, in which air resistance is neglected and the
acceleration is nearly constant, is known as free-fall.

Since the acceleration is constant in free-fall, the equations of kinematics can be used.

Acceleration Due to Gravity

The acceleration of a freely falling body is called the acceleration due to gravity, g.

The acceleration due to gravity is directed downward, toward the center
of the earth.

Near the earth's surface, g =
9.80 m/s<sup>2, down.

Heavy and light objects fall at the same rate

A Falling Stone

A stone is dropped from rest from the top of a tall building, as the
figure indicates.

After 3.00 s of free-fall,  

 a. what is the velocity v of the stone?

b. what is the displacement y of the stone?

Coin Toss

A football game customarily begins with a coin toss to determine who
kicks off. The referee tosses the coin up with an initial speed of 6.00 m/s. In the absence
of air resistance, how high does the coin go above its point of release?

What is the velocity and acceleration at the maximum height?

2.7 Graphical Analysis of Motion

First we will graphically look at a motion where a person walks at
a constant velocity along a straight-line path.

2.7 Graphical Analysis of Motion

First we will graphically look at a motion where a person walks at
a constant velocity along a straight-line path.

Can you plot the position, x (m) versus time, t (s) graph?

Position VS. Time graph

What is the slope of the position VS. time graph?

Position VS. Time graph

What is the slope of the position VS. time graph?

EXAMPLE 16 A Bicycle Trip

A bicyclist maintains a constant velocity on the outgoing leg of a journey, zero velocity while stopped for
lunch, and another constant velocity on the way back.

Velocity versus Time graph

A car is moving along a straight-line path starting from rest at a
constant acceleration. Once the car reaches a velocity of 45 MPH, that
velocity is maintained for a while. Finally the brakes are applied with
a constant deceleration and the car comes to rest.

Velocity versus Time graph

A car is moving along a straight-line path starting from rest at a
constant acceleration. Once the car reaches a velocity of 45 MPH, that
velocity is maintained for a while. Finally the brakes are applied wit