Hint
Use the stated units and precision. Use a perpendicular prism length rather than a sloping side.
Worked solution
(a)
Use a perpendicular prism length rather than a sloping side.
Multiply cross-sectional area by length: \(\displaystyle 49 \mathrm{cm}^{3}\).
Answer: \(49\)
(b)
Square the radius and multiply by height.
The coefficient \(\displaystyle r^{2}h\) is 36.
Answer: \(36\)
(c)
Use circumference times height for the curved surface.
Unrolling the curved surface gives coefficient 2rh=36.
Answer: \(36\)
Maths4U indicative marking guidance
Maths4U indicative marking guidance, not an official mark scheme. Credit complete valid alternative methods and consequential reasoning. An unexplained result does not earn a method mark.
(a) · 2 marks
- 1 mark: Use a perpendicular prism length rather than a sloping side.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
(b) · 2 marks
- 1 mark: Square the radius and multiply by height.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Check the answer against the original conditions.
(c) · 2 marks
- 1 mark: Use circumference times height for the curved surface.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
Total: 6 marks.