Date | November 2019 | Marks available | 3 | Reference code | 19N.3.SL.TZ0.1 |
Level | Standard level | Paper | Paper 3 | Time zone | 0 - no time zone |
Command term | Determine | Question number | 1 | Adapted from | N/A |
Question
A student investigates how the period T of a simple pendulum varies with the maximum speed v of the pendulum’s bob by releasing the pendulum from rest from different initial angles. A graph of the variation of T with v is plotted.
Suggest, by reference to the graph, why it is unlikely that the relationship between T and v is linear.
Determine the fractional uncertainty in v when T = 2.115 s, correct to one significant figure.
The student hypothesizes that the relationship between T and v is T = a + bv2, where a and b are constants. To verify this hypothesis a graph showing the variation of T with v2 is plotted. The graph shows the data and the line of best fit.
Determine b, giving an appropriate unit for b.
The lines of the minimum and maximum gradient are shown.
Estimate the absolute uncertainty in a.
Markscheme
a straight line cannot be drawn through all error bars
OR
the graph/line of best fit is /curved/not straight/parabolic etc.
OR
graph has increasing/variable gradient ✔
NOTE: Do not allow “a line cannot be drawn through all error bars” without specifying “straight”.
AND ✔
«»0.04 ✔
NOTE: Accept 4 %
use of 2 correct points on the line with Δv2 > 2 ✔
b in range 0.012 to 0.013 ✔
s3 m–2 ✔
«s» ±0.001 «s» AND «s» ±0.001 «s» ✔
«» 0.003 «s» ✔