DP Physics (last assessment 2024)

Question 19N.3.SL.TZ0.1

Date	November 2019	Marks available	[Maximum mark: 8]	Reference code	19N.3.SL.TZ0.1
Level	SL	Paper	3	Time zone	TZ0
Command term	Determine, Estimate, Suggest	Question number	1	Adapted from	N/A

[Maximum mark: 8]

19N.3.SL.TZ0.1

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.

(a)

Suggest, by reference to the graph, why it is unlikely that the relationship between T and v is linear.

[1]

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”.

(b)

Determine the fractional uncertainty in v when T = 2.115 s, correct to one significant figure.

[2]

Markscheme

$v = 1.15 « m s^{- 1} »$ AND $∆ v = 0.05 « m s^{- 1} »$ ✔

« $\frac{0.05}{1.15} =$ »0.04 ✔

NOTE: Accept 4 %

(c)

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.

[3]

Markscheme

use of 2 correct points on the line with Δv²> 2 ✔

b in range 0.012 to 0.013 ✔

s³m^–2✔