# Dimensional Motion—Design Lab

#### Dimensional Motion—Design Lab

Purpose: To determine the muzzle velocity(vi) of a Nerf.

Materials:

• Stopwatch
• Nerf Gun
• Slope finder App to make sure it is 90 degrees straight up.

Procedure:

1. Fire Nerf Gun vertically, at 90 degrees, use the slope finder App to make sure it is 90 degrees straight up. Determine the time when a bullet is fired and when it lands (total time).
2. Divide time by 2 to find the time of when the bullet gets to the peak height.

Total Time/2 = Time gets to the peak height.

1. Record the data below.
2. Use the Kinematic equation to calculate the initial velocity.

Formula: Vf=Vo+at

1. Find percent difference (keep 3 sig figs) between your groups vs. other groups.

% difference= |your group data – other groups data| x 100%
Average data

Data: Nerf Gun chart

 Total time(s) Time for going upward(s) Vf(m/s) Vo=? (m/s) [upward] 1 4.20 2.11 0 20.7 2 4.13 2.07 0 20.3 3 4.36 2.18 0 21.4 4 4.05 2.03 0 19.9 5 3.80 1.90 0 18.6 Average 4.11 2.06 0 20.2

Calculations:

Show all work clearly. % difference:

% difference= |your group data – other groups data| x 100%
Average data Conclusion:

In this lab, we studied the muzzle velocity of a Nerf Gun. Because the bullet reaches the highest point and then landed at half the time the bullets reached the highest point, our time will be divided by the total time recorded. (Total Time/2 = Time gets to the peak height.) Then use the calculation formula (Vf = Vo + at) to get the initial velocity. Combining these two equations, we get the result of our initial velocity of a nerf gun is 20.2m/s

Errors in this lab came from our measurement. No measurement can be perfect. Measurements always have some uncertainty. Due to the presence of measurement uncertainty, measured values will never be equal to predicted values. This causes our error value with other groups to be around 8-18%. If we experiment on a sunny day instead of a rainy day, the results will improve, as this will not use images for the weight of the bullet. Second, the wind has a large impact on the data, which will affect the direction of the bullet, which may increase the time the bullet stays in the air. If done correctly, this will reduce our error in calculating time.

Designed by: Lina, Bianca, Grace

Oct. 15, 2019