Week 1 - Free Falling

OBJECTIVE:

To Simulate and plot a freefalling body (point mass) of mass 1 kg and inertial properties 1 kgm2 in the y-axis with simulation time of 2sec

THEORY:

Free Falling Object: The term "free fall" refers to an object falling freely with no forces operating on it other than gravity.

Mathematical equation for free falling object

`h=1/2(g*t^2)`

here,

h - Distance travelled by object in m

g - Acceleration due to gravity in m/s2

t - time elapsed in s.

SIMULATION:

Before creating the point mass, the gravity and units in the motionview User Interface is modified to the requirement.

Now, in the motion view graphic user interface, a point mass with mass 1kg and inertial characteristics of 1kgm2 in lyy is produced, and the global origin is used as the origin point within the centre of mass co-ordinate system.

note: as moment of inertia is not mention for x and z direction, the value is reduced to the minimum value that the solver can take, but the end results are not affected by this.

The simulation is then conducted after the simulation end time is set to 2 seconds.

After the simulation is completed, the plot option is selected, and the needed graph (Disp of point mass in Y-direction versus Time) is displayed, allowing us to calculate the distance travelled by the body after 2 seconds.

2. Does the mass and inertial properties of the body depend on the rate of fall? Justify your answer with analytical (with equation) and simulation results.

It is obvious from the preceding equation that the rate of fall is independent of mass and inertial characteristics.

Assume a body, one of mass 1 kg and inertial properties of 1kgm2

Substituting in equation

`h = 1/2(g*t^2)`

`h = 1/2*9.81*2^2`

`h = 19.62m`

The rate of descent would remain constant, as evidenced by the fact that the distance travelled over the same time span would be the same.

3. In what case will the mass have an effect on the rate of fall? In the same case what other physical characteristics will affect the rate of fall?

The situation of air resistance must be considered for the mass to have an influence on the rate of descent.

The two most prevalent causes that have an immediate impact on air resistance are

• The object's velocity
• The object's cross-sectional area

The rate of fall is affected by the density of the fluid, the drag coefficient and velocity, the drag area, and other physical parameters.