Question

1-D Kinematics

Experiment 1: Free Fall

In this experiment you will drop the hex nut from different heights. You will explore how height from which the hex nut is dropped affects its falling time and its final velocity.

Materials: Hex nut Stopwatch Tape Measure

Procedure

1. a) Write down a hypothesis how height will affect the falling time of an object. (Note: use form: if…… then……)

2. b) Write down a hypothesis how height will affect final velocity of the falling object. (Note: use form: if…… then……)

3. Drop the hex nut from different heights. For each drop, measure the distance from the ground and the time the hex nut is falling down. For each height do at least three measurements of falling time and then calculate the average time.  

Include your measurements in Table 1.

4. Calculate final velocity of falling hex nut using equation:

v = v₀ + at   

Since the initial velocity (the one you start with) in this experiment is always equal to 0 m/s, then the equation you use for calculation is simply:

v = at

Example:

If average t = 2.5 seconds then,

     

    v = a (2.5 s)   

Since an object is in free fall, acceleration a is equal to gravitational acceleration g = 9.8 m/s².

Therefore,

  

v = (9.8 m/s²)(2.5 s) = 24.5 m/s

5. Include your calculated values of the final velocity in Table 1.

Data:

Table 1

Height (m)	Time (s)	Average Time (s)	Final Velocity (m/s)

6. Plot time versus height graph using your data from Table 1 (Note: independent variable is on the x axis and depended variable is on y axis)

Independent Variable: _____________

Dependent Variable: ________________

[include your graph here]

7. Plot final velocity versus height graph using your data from Table 1.

Independent Variable: _____________

Dependent Variable: ________________

[include your graph here]

Answer 1

a) Write down a hypothesis how height will affect the falling time of an object.

If we increase the height, then hex nut will take more time reach the ground

If we decrease the height, then hex nut will reach the ground soon.

b)  Write down a hypothesis how height will affect final velocity of the falling object.

as per the equation v = sqrt (2gh) . If we increase the height, the final velocity just before impact will be increasing.

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As it is an experiment based, I will take my own random height value. You can take your own, method however will be the same.

Height (m)	time (s)	average time	velocity
10	1.43, 1.4, 1.435	1.42	13.916 m/s
20	2, 2.02, 2.05	2.023	19.828 m/s
30	2.45, 2.43, 2.47	2.45	24.01

Now, to plot the graph of time vs height.

Here height is independent variable and time is dependent variable

Notice that we get a straight line.

Similarly, in velocity vs height graph, height is independent and velocity is dependent.