March-23-2015 Lab 7: Trajectories

Lab 7: Trajectories

Purpose: To use understanding of projectile motion to predict the impact of a ball on an inclined board.

Material: Aluminum "V-channel", steel ball, board, ring stand, clamp, cartoon paper.

By preidict the result and measure it, should compare with those two results.

To predict the impact of a ball on the inclined.

1).Set up the apparatus as shown.

2).Launch the ball from a readily

same point, and notice that point.

3).Tape a piece of carbon paper to

the floor around where the ball landed.

launch the ball five times from the 

same spot.

4)Determine the height of the bottom of 

the ball when it launches, and how far out

from the table's edge it lands.

In order to test the calculate the result. Measure the height of the ball from the table, 

Phase one:

obtain the predict result of landing distance.

Then we got the speed of the ball when it fly out from the board.

SO height h = 0.94M  distance x = 0.553 m time t = 0.438s
the speed of the ball is v = 1.26 m/s

5) Imagine attaching an inclined board at the edge of the lab table such that the ball launched at the same spot before, will strike the board a distance d along the board. record the angle between the board and the ground.

This picture just show you how this work

get the angle a and d.

Then we predict the distance d with angle 48 + - 1 degree v = 1.26 m/s

d= 0.538m  x = 0.359m  y = 0.399m

Phase two

To get the measured landing distance. 

We also measure the d, x y  by our hands which has uncertainty on it.
first we measure the height from the point to the table and the angle with uncertainty in it. and then we get the distance d.

This is the distance d we measured by our hands. so our prediction is in between the d we measured.
So our prediction is acceptable. that's mean our experiment is good.

Conclusion

For this experiment, we get the results by prediction and measurement, it turns out the those two results are reasonable,