User's Manual

Model No. ME-6830 Teacher’s Guide

012-05375C 51

Teacher’s Guide

Exp. 1: Projectile Motion

NOTE: For best results, make sure that the Launcher is securely clamped to a sturdy table. Any movement of the

Launcher will result in inconsistent data.

The muzzle speed of the Launcher tested was 6.5 m/s (on the long range setting).

To find the range at the chosen angle, it is necessary to solve the quadratic equation given in the Theory section.

The solution is:

Analysis

1. The difference depended on the angle at which the Launcher was fired. The table gives typical results: range

NOTE: The maximum angle is not 45° in this case. The range at 60° is not equal to the range at 30°. This is

because the initial height of the ball is not the same as the impact point. The maximum range for this setup

(with the Launcher 1.15 m above ground level) was calculated to be at 39°. This was verified experimentally.

2. Answers will vary depending on the method for estimating the precision. The primary source of error is ignor-

ing the effect of air resistance.

Exp. 2: Projectile Motion Using Photogates

Except for the method of determining initial speed, this experiment is identical to experiment 1.

Angle Predicted Range Actual Range Percent Error

30 5.22 5.19 0.57%

45 5.30 5.16 2.64%

60 4.35 4.23 2.87%

39 5.39 5.31 1.48%

 v

sin

2gy

y–++sin

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