Lab Report on Newton’s Second Law: Constant Force
The goal of this experiment was to take a practical approach to studying Newton’s Second Law and understanding the relationship between acceleration, force, and mass. In event, we confirmed this law that states: the acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to the object’s mass (Loyd 101).
Description of experiment
In this experiment, we confirmed Newton’s Second Law by performing two related activities in which we measured the acceleration of system under the following circumstances:
i. The acceleration of the system as a result of variation in net external force, holding mass constant.
ii. The acceleration of the system upon doubling of the mass, holding the external force constant.
i. If a greater net force pulls on an object with a constant mass, acceleration of the system increases.
ii. When the mass is doubled and the external force held constant, the acceleration of the system reduces.
The following list of materials was used in the experiment:
venire motion detector– used to measure the acceleration of the car
Computer – used for the software
logger pro – used to show the graphs and do some of the measuring
Dynamics Carts
Force Sensor
We employed the following geometry of Newton’s Second Law for both activities:
In activity I the force was held constant while the force was varied. A cart was rested on a smooth horizontal surface with a sensor on it and an object was attached to it using a light tape hanging over the pulley. We began started off with a mass of 50g. We measured and recorded the velocity (m/s) and time (s) for various positions over which the cart had moved on the horizontal surface. We repeated the process using additional masses to obtain 70g, 90g and finally 100g. We made two assumptions: that the weight of the tape and the friction between the cart and the surface were negligible. We then used the sensor to produce a position versus time graph and a velocity versus time graph (see Appendix 1). A near linear graph was obtained, the slope of which represented the constant acceleration of the system. The outcome was compared to prediction 1.
In activity II, the value of the mass was being increased while the force remained constant. Using the same system, we started with a hanging mass of 20g and determined the mass of the cart and the value on the Force Sensor. We then matched the result with the acceleration obtained in activity one for the same mass. We repeated the procedure for an additional mass of 250g on the Sensor. The procedure was repeated twice, by adding a 250g mass each time. A graph of mass versus acceleration (Appendix 3) was produced and the result compared to prediction 2.
Results analysis and conclusion
The graph shows the outcome of activity one. In this activity, we found that acceleration was increasing when mass is held constant while increasing the force. The two variables in the system, that is force and acceleration, were directly related. In activity 2, we found that while the mass was increasing, acceleration was decreasing. The two were inversely proportional. From the two results, the following simple rule arose: the acceleration of an object is directly related to the force causing it and inversely related to its mass. This simple conclusion resonates with the predictions we made at the preliminary stage of the experiment. On that account, the results are consistent with Newton’s Second Law, thus verifying it.
Works Cited
Loyd, David. (2007) Physics Laboratory Manual. New York: Sage Publications. Print.
Appendix 1: Graph of velocity versus time holding mass constant while varying velocity.
Appendix 2:
