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WorksheetsErrors and measurement of physical quantities
Total questions: 10
Worksheet time: 8mins
1. In an experiment, a radio-controlled car takes 2.50 ± 0.05s to travel 40.0 ± 0.1m.
What is the car’s average speed and the uncertainty in this value?
16 ± 1ms-1
16.0 ± 0.2ms-1
16.0 ± 0.4ms-1
16.00 ± 0.36ms-1
A mass is dropped from rest, and falls through a distance of 2.0m in a vacuum. An observer records the time taken for the mass to fall through this distance using a manually operated stopwatch and repeats the measurements a further two times. The average result of these measured times, displayed in the table below, was used to determine a value for the acceleration of free fall. This was calculated to be 9.8ms-2.
Which statement best relates to the experiment?
The measurements are precise and accurate with no evidence of random errors.
The measurements are not accurate and not always recorded to the degree of precision of the measuring device but the calculated experimental result is accurate.
The measurements are not always recorded to the degree of precision of the measuring device but are accurate. Systematic errors may be present.
The range of results shows that there were random errors made but the calculated value is correct so the experiment was successful.
Variables x and y are related by the equation y = p– qx where p and q are constants. Values of x and y are measured experimentally. The results contain a systematic error. Which graph best represents these results?
A
B
C
D
The speed of a car is calculated from measurements of the distance travelled and the time taken. The distance is measured as 200m, with an uncertainty of ±2m. The time is measured as 10.0s, with an uncertainty of ±0.2s. What is the percentage uncertainty in the calculated speed?
±0.5%
±1%
±2%
±3%
In an experiment to determine the acceleration of free fall g, the time t taken for a ball to fall through distance s was measured. The uncertainty in the measurement of s is estimated to be 2%. The uncertainty in the measurement of t is estimated to be 3%. The value of g is determined using the equation:
What is the uncertainty in the calculated value of g?
1%
5%
8%
11%
Which experimental technique reduces the systematic error of the quantity being investigated?
adjusting an ammeter to remove its zero error before measuring a current
measuring several internodal distances on a standing wave to find the mean intermodal distance
measuring the diameter of a wire repeatedly and calculating the average
timing a large number of oscillations to find a period.
A force of 5 N may be represented by two perpendicular components OY and OX as shown in the diagram, which is not drawn to scale. OY is of magnitude 3 N. What is the magnitude of OX?
2N
3N
4N
5N
Four students each made a series of measurements of the free fall g. The table shows the results obtained. Which set of results could be described as precise but not accurate?
А
В
С
D
Four different students use a ruler to measure the length of a 15.0cm pencil. Their measurements are recorded on four different charts. Which chart shows measurements that are precise but not accurate?
A
B
C
D
The density of the material of a coil of thin wire is to be found. Which set of instruments could be used to do this most accurately?
metre rule, protractor, spring balance
micrometer, metre rule, top-pan balance
stopwatch, newton-meter, vernier calipers
tape measure, vernier calipers, lever balance
