| Date | May 2011 | Marks available | 3 | Reference code | 11M.1.sl.TZ1.5 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Calculate | Question number | 5 | Adapted from | N/A |
Question
A satellite travels around the Earth in a circular orbit \(500\) kilometres above the Earth’s surface. The radius of the Earth is taken as \(6400\) kilometres.
Write down the radius of the satellite’s orbit.
Calculate the distance travelled by the satellite in one orbit of the Earth. Give your answer correct to the nearest km.
Write down your answer to (b) in the form \(a \times {10^k}\) , where \(1 \leqslant a < 10{\text{, }}k \in \mathbb{Z}\) .
Markscheme
\(6900\) km (A1) (C1)
[1 mark]
\(2\pi (6900)\) (M1)(A1)(ft)
Notes: Award (M1) for substitution into circumference formula, (A1)(ft) for correct substitution. Follow through from part (a).
\( = 43354\) (A1)(ft) (C3)
Notes: Follow through from part (a). The final (A1) is awarded for rounding their answer correct to the nearest km. Award (A2) for \(43 400\) shown with no working.
[3 marks]
\(4.3354 \times {10^4}\) (A1)(ft)(A1)(ft) (C2)
Notes: Award (A1)(ft) for \(4.3354\), (A1)(ft) for \( \times {10^4}\) . Follow through from part (b). Accept \(4.34 \times {10^4}\) .
[2 marks]
Examiners report
Candidates appeared to be confused by the context in this question. They had difficulty identifying the radius and many used the formula for the area of a circle, rather than the circumference.
Candidates appeared to be confused by the context in this question. They had difficulty identifying the radius and many used the formula for the area of a circle, rather than the circumference. A large number of candidates misread the final sentence in part b and did not write their answer to the nearest kilometre.
Candidates appeared to be confused by the context in this question. They had difficulty identifying the radius and many used the formula for the area of a circle, rather than the circumference.
