Show an example of your calculation of the launch velocity of the rocket as a function of flight time.

Show your calculations of the predicted range for the three angles used.

Procedure 3 - Rocket Launch, determining launch velocity.

Rocket experiment

• The best results occur when you have a consistent squeeze on the launch bulb, firm but not excessively vigorous. The rocket flies more consistently and travels a manageable distance from a measurement perspective.
• Before collecting data, make sure you practice you launch technique. Try to squeeze the launch bulb in a consistent manner to minimize experimental variation.
• Launch the rocket close to the ground for your range measurements.

In this experiment you will launch a rocket vertically, straight up, and measure the time of flight. We can use either the time to reach the peak of flight or the total time of flight. Measuring the total time of flight is recommended as a longer time is less affected by reaction times in operating the stopwatch.

The time to reach the peak is the total time of flight.

Let t = time to reach peak

v = 0 at the peak

v = v₀ - gt

0 = v₀ - 9.8 t

V₀ = 9.8 t

Perform 10 trials, measure the flight time, and calculate the initial velocity. Remember the equation above uses the time to peak of flight, the flight time.

Data table for rocket experiment - vertical launch

Trial Number	Flight time (sec)	Calculated velocity (m/s)
1	0.82 s	4.0 m/s
2	0.98 s	4.8 m/s
3	0.74 s	3.65 m/s
4	0.52 s	2.55 m/s
5	0.66 s	3.25 m/s
6	0.74 s	3.65 m/s
7	0.79 s	3.85 m/s
8	0.88 s	4.3 m/s
9	0.98 s	4.8 m/s
10	0.95 s	4.65 m/s
Average	0.806 s	4.7 m/s
Standard Deviation	S = 0.149	S = 0.72

Procedure 4 - Rocket Launch at Angles

Using a protractor set the rocket to launch at angles of 30^o,45^o, and 60^o.

You will use the range equation to predict the horizontal distance the rocket travels.

R =() sin (2):where theta () is the launch angle (measured from the horizontal). This is equation 4-12 on page 104 of your text.

Data tables for rocket experiment - angle experiments

Angle = 30^o

Trial Number	Predicted range (meters)	Measured range (meters)	Difference (meters)
1	1.95 m	3.8 m	1.85 m
2	1.95 m	1.8 m	0.15 m
3	1.95 m	1.16 m	0.79 m
4	1.95 m	1.48 m	0.47 m
5	1.95 m	2.05 m	0.1 m
Average	1.95 m	2.05 m	0.67 m
Standard Deviation		S = 1.03	S = 0.71

Angle = 45^o

Trial Number	Predicted range (meters)	Measured range (meters)	Difference (meters)
1	2.25 m	4.0 m	1.75 m
2	2.25 m	3.8 m	1.55 m
3	2.25 m	3.65 m	1.4 m
4	2.25 m	3.7 m	1.45 m
5	2.25 m	3.5 m	1.25 m
Average	2.25 m	3.73 m	1.48 m
Standard Deviation		S = 0.186	S = 0.186

Angle = 60^o

Trial Number	Predicted range (meters)	Measured range (meters)	Difference (meters)
1	1.95 m	1.2 m	0.75 m
2	1.95 m	2.64 m	0.69 m
3	1.95 m	1.72 m	0.23 m
4	1.95 m	2.0 m	0.05 m
5	1.95 m	1.34 m	0.61 m
Average	1.95 m	1.78 m	0.47 m
Standard Deviation		S = 0.575	S = 0.308

Rocket calculations

Show an example of your calculation of the launch velocity of the rocket as a function of flight time.

V = 9.8*t

V = 9.8 * 0.82 m/s = 8.0 m/s

V = 8.0 m/s

Show your calculations of the predicted range for the three angles used.

Given that t (total time of flight) and g (acceleration due to gravity on Earth's surface) = 9.81 m/s²and the average velocity of the rocket calculationsis 7.9 m/s.

Angle 30^o

R =() sin (2)

R =( ) *sin (2*30^o)= 1.95 m

Angle 45^o

R =() sin (2)

R =( ) *sin (2*45^o)= 2.25 m

Angle 60^o

R =() sin (2)

R =( ) *sin (2*60^o)= 1.95 m