Pendulum Practicum Physics

Before the Lab Data Collection: Height of Ramp: Distance to Floor: (What you will measure.) h d h d Have a student measure the height of the ramp and the distance from the counter to the floor. Everyone will write it down. Height of the Ramp: .44 m ish Distance to Floor: .94 m ish Before the Lab Just use the ramp height for Part 1 Just use the distance for Part 2

Part 1 = Energy mghtop mgh1/2 + ½ mv2 ½ mv2 First we will solve for the launch speed by using the conservation of energy. Draw an energy pie chart for the marble at the top of the ramp, middle of the ramp, and bottom of the ramp. DON’T INCLUDE HEAT!!! mghtop mgh1/2 + ½ mv2 ½ mv2 Part 1 = Energy

What is the height the marble fell from the top of the ramp to the bottom of the ramp? How much gravity energy did we have up on top? (Just leave the unknown mass as ‘m’.) What kind of energy do we have at the bottom? e. Conservation says that part c and part d should be equal. Use this to solve for the launch velocity. height we measured mgh Kinetic ½ mv2 mgh = ½ mv2 Solve for v Part 1 = Energy

Part 2 = Two Dimensional Kinematics Use kinematics in the y-dimension to solve for the drop time of the marble. Y-DIM Equation: Solve for t. x = v o = v = Drop time = a = t = x = ½ at2 + vot t = √2∆x/a d (distance to floor) 0 m/s Impact velocity (DC) 9.8 m/s2 want About .2 s is a good number for the time. Have them plug in numbers and check their answers with the class. Part 2 = Two Dimensional Kinematics

Part 2 = Two Dimensional Kinematics Use common sense in the x-dimension to solve for how far the marble will move forward in this time. Remember that the horizontal speed of the marble equals the speed we calculated in part one using energy. Y-DIM Equation: Solve for x. . x = v = c= t = v = x/t ∆x = v∆t landing length (want) Velocity from Part 1 time from part 2.a. x is where you place the target. In my classroom it should be about 1.28 m-ish. Part 2 = Two Dimensional Kinematics

Pendulum Practicum Lab DON’T FORGET ABOUT AIR RESISTANCE! PLACE THE BACK OF THE TARGET AT THE PREDICTION POINT!