Phy 213 Experiment 5: Force Concepts Application I

Deliverable: (means what you must deliver) The rolling friction force of a PASCO cart.

Method:

• Place the cart on an incline, with the motion detector at the bottom of the ramp, ( see figure).

• Give the cart a shove up the plane.

• Analyze the velocity vs time graph to obtain the acceleration up the plane, a_up and the acceleration down the plane, and. Use these two different values of acceleration along with the mass of the cart to obtain the rolling friction force of the cart.

Procedure:

1. Before doing this lab, each of you individually must turn in a sheet containing the following:

-FBD of the cart when traveling up the ramp, including x and y axes. (Make up the ramp positive)

-Equation of sum of forces in both x and y directions.

-FBD of the cart when traveling down the plane, including x and y axes. (Make up the ramp positive)

-Equation of sum of forces in both x and y directions .

-Algebra solving the above equations for F_R , the rolling friction of the cart.

-This equation will include only symbols F_R , m, for mass of the cart, a_up, acceleration of the cart when moving up the plane, and a_dn, acceleration of the cart when moving down the plane.

PS: The algebra must be very convincing.

2. Now get into groups and actually shove the cart up the plane to obtain values of a_dn and a_up. Plug these into your formula for F_R , do a brief write up and turn it in today.

Alternate Method:

Find the component of gravity F_gx in the direction of the plane and use it to obtain the rolling friction force. (What data must be taken in order to find F_gx ?) And, you've still godda show the algebra.