AP PHYSICS I "WHIRLIGIG" LABORATORY INTRODUCTION This experiment involves centripetal force, the force that keeps objects moving in a circular path. This force is perpendicular to the motion and directed towards the center of the circular orbit. By Newton's Second Law when a centripetal force acts on a mass (in a horizontal plane), the force continually changes the direction of the velocity without changing its magnitude, speed. This change in the direction of the velocity accounts for the centripetal acceleration of the mass, whose direction is towards the center. The relationship between the centripetal force, mass of the orbiting object, and its speed and distance from the center is described by: ту? Fc%3D hollow tube EXPERIMENTAL DESCRIPTION string (1m) loop in string In this lab two students constructed the spinning device shown in the above picture to study centripetal force. A string was threaded through a hollow tube (with curved edges to reduce friction) and a mass was tied to one end of the string and a plastic tie hooked maS second mass was tied to the other end. The first mass was stopper allowed to hang while one student held onto the tube and twirled the second mass in an almost horizontal circle with a constant radius of 0.50 m. The other student used a timer to measure the period of the second mass as it swung in a circular orbit. The students then switched out the hanging mass for a different mass and measured the period of the new mass. They repeated this process for 5 different masses. Throughout these trials, the rotating mass and radius of the circle remained constant. Below is the data table (representing the average values) for the laboratory. You will use it to analyze the experiment. Hanging Mass, mh (kg) Speed, v (m/s) 0.05 2.10 0.10 4.40 0.20 6.50 0.30 7.75 0.40 9.20 0.50 10.60 LABORATORY ANALYSIS EXTENSION QUESTION: When twirling the mass, students found that despite their best efforts, they could not swing the ball so that the cord remained exactly horizontal. 8. (a) On the diagram of the rotating mass below, draw a force diagram of the forces acting on the mass and identify each force. Do not include any force components in this diagram. center of circle (b) Explain why it is not possible for the ball to swing so that the cord remains exactly horizontal. Write your answer using complete sentences.

AP PHYSICS I "WHIRLIGIG" LABORATORY INTRODUCTION This experiment involves centripetal force, the force that keeps objects moving in a circular path. This force is perpendicular to the motion and directed towards the center of the circular orbit. By Newton's Second Law when a centripetal force acts on a mass (in a horizontal plane), the force continually changes the direction of the velocity without changing its magnitude, speed. This change in the direction of the velocity accounts for the centripetal acceleration of the mass, whose direction is towards the center. The relationship between the centripetal force, mass of the orbiting object, and its speed and distance from the center is described by: ту? Fc%3D hollow tube EXPERIMENTAL DESCRIPTION string (1m) loop in string In this lab two students constructed the spinning device shown in the above picture to study centripetal force. A string was threaded through a hollow tube (with curved edges to reduce friction) and a mass was tied to one end of the string and a plastic tie hooked maS second mass was tied to the other end. The first mass was stopper allowed to hang while one student held onto the tube and twirled the second mass in an almost horizontal circle with a constant radius of 0.50 m. The other student used a timer to measure the period of the second mass as it swung in a circular orbit. The students then switched out the hanging mass for a different mass and measured the period of the new mass. They repeated this process for 5 different masses. Throughout these trials, the rotating mass and radius of the circle remained constant. Below is the data table (representing the average values) for the laboratory. You will use it to analyze the experiment. Hanging Mass, mh (kg) Speed, v (m/s) 0.05 2.10 0.10 4.40 0.20 6.50 0.30 7.75 0.40 9.20 0.50 10.60 LABORATORY ANALYSIS EXTENSION QUESTION: When twirling the mass, students found that despite their best efforts, they could not swing the ball so that the cord remained exactly horizontal. 8. (a) On the diagram of the rotating mass below, draw a force diagram of the forces acting on the mass and identify each force. Do not include any force components in this diagram. center of circle (b) Explain why it is not possible for the ball to swing so that the cord remains exactly horizontal. Write your answer using complete sentences.