Parallel
Forces on an Incline
Objective: Determine
the relationship between angle of inclination and the
force needed to keep cart from rolling.
Materials:
board, protractor, cart, balance
Methods
1. Sketch the set up
with the board at 45o.
2. Review Pg 124 and
note the component of gravity parallel to the incline, the force responsible
for the cart rolling down the incline.
Label all the vector components on your sketch.
3. Set the incline
at angles between 0o and 90o as described.
For each angle, record the force in Newtons on the scale.
This force prevents the cart from rolling.
Use 10o increments.
4.
Find the mass of the cart and calculate its weight (g = 9.8 m/s2).
Analysis
1. Plot a graph of
the parallel force (y-axis) as a function of angle θ.
Connect the data points with a smooth curved line.
2.
Now, plot on the same graph the product of
(weight of cart) x
(sin θ) at each angle θ.
3.
From the graph, write an equation relating the
parallel force, the weight of cart, and sin θ.
4. Using the graph,
estimate by interpolation the approximate angle when the
parallel force =
1/2 the weight of the cart.
Find
the sine of this angle and draw a conclusion.
5.
Summary
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