A physics club designs an experiment in which three different constant horizontal…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A physics club designs an experiment in which three different constant horizontal forces are applied to the same low-friction cart, and the resulting accelerations are measured. The collected data are shown in the table below.
Trial
Applied Horizontal Force F (N)
Measured Acceleration a (m·s−2)
1
1.5
0.50
2
3.0
1.02
3
4.5
1.53
The uncertainty in each force measurement is ±0.05N, and the uncertainty in each acceleration measurement is ±0.02m⋅s−2.
(1) Using the data, calculate the numerical value of the slope of a best-fit straight line for a graph of applied force (vertical axis) versus acceleration (horizontal axis). Show how you obtain the slope from the data.
(2) Interpret the physical meaning of the slope obtained in part (a) in the context of the cart’s motion. State an appropriate value (with units) for the cart’s mass based on your calculated slope.
(3) The best-fit line has a small, non-zero y-intercept. Explain what a non-zero y-intercept would indicate about unaccounted-for forces in the experiment.