End of topic questions Note: The marks awarded for these questions indicate the level of detail required in the answers. In the examination, the number of marks awarded for questions like these may be different.
1. Rules that are 30 cm long are often made of wood or plastic that is thicker in the middle and thinner along the edges where the scale is printed. Explain why the user is less likely to make an error if the rule is thinner at the edge, and suggest (3 marks) reasons why the rule is thicker in the middle. 2. A plastic measuring cylinder is filled with water to the 100 cm3 mark. A student measures the column of water in the cylinder with a rule and finds that it is 20 cm high. a) The student pours 10 cm3 of the water out of the cylinder. How high will the (2 marks) column of water be now? b) The student then refills the cylinder back to the 100 cm3 mark by holding it under a dripping tap. She finds that it takes 180 drops of water to do this. What (3 marks) is the volume of one of these drops? c) What is the c ross-sectional area of the cylinder? (Hint: The volume of a cylinder (3 marks) is given by the equation: volume = cross-sectional area × length.) d) From your answer to part c), what is the internal diameter of the measuring (3 marks) cylinder? 3. A student tries to measure the period of a pendulum that is already swinging left and right. At the moment when the pendulum is fully to the left, she counts ‘one’ and starts a stopwatch. She counts successive swings each time that the pendulum returns to the left. When she counts ‘ten’ she stops the stopwatch, and sees that it reads 12.0 s. a) What was her mistake?
(2 marks)
b) What is the period of swing of this pendulum?
(3 marks)
c) In this particular experiment, explain the likely effect of her reaction time on (3 marks) her answer.
15
Length and time
4. EXTENDED What is the distance that has been measured by this micrometer thimble (1 mark) screw gauge?
92678_P008_131.indd 15
7/8/14 10:41 AM