Compound Measures: WJEC GCSE Intermediate November 2019 Unit 2 Q16

Intermediate November 2019 Unit 2 Q16

WJECIntermediateCurrent spec6 marksCompound Measures Volume & Surface Area

16. A solid object is made by drilling a cylindrical hole of radius 4 cm through a cuboid measuring 20 cm by 15 cm by 10 cm as shown below.

Cuboid 20 cm by 15 cm by 10 cm with a vertical cylindrical hole of radius 4 cm through it

Diagram not drawn to scale

(a) Calculate the volume of the object.
Give your answer in cm³. [3]

Volume = ……………… cm³

(b) The object is made from a material which has a density of 2·4 g/cm³.
Calculate the mass of the object.
Give your answer in kg, correct to the nearest kg. [3]

Mass = ……………… kg

Mark scheme (a)

Scheme	Marks	Comments
20 × 15 – π × 4²	M1
× 10	m1
2497(·….) OR 3000 − 160 π	A1	Accept an answer between 2497 and 2498 inclusive OR 2500. SC1 for sight of π × 4² × 10 OR 160 π (accept 502 to 503 inclusive).

Mark scheme (b)

Scheme	Marks	Comments
(Mass =) 2497·(..) × 2·4 OR 2497·(..) × 0·0024	M1	F.T. ‘their volume in (a)’
= 5993·6(..)(g) OR 5·9936..(kg)	A1	Accept value truncated or rounded to a whole number. Ignore units.
6(kg)	A1	F.T. from ‘their 5993·6..g’ or ‘their 5·9936..kg’ ONLY if M1 awarded AND ‘their 5993·6..g’ > 500g or ‘their 5·9936..kg’ > 0.5kg If no marks awarded, allow SC1 for (Mass =) ‘their volume’ × density, where density may have incorrect place value e.g. ‘2497·(..) × 0·024’