Work through these eight questions in order. They cover all four lessons in space technology. Take the speed of radio waves as 3 × 10⁸ m/s and g as 10 m/s².
The timed practice session builder can turn the set into a timed run.
Questions
Question 1 (2 marks). A fishing boat in open sea needs to know its position. Name the satellite function it uses and give one reason.
Answer
Navigation. Signals from satellites let the boat work out its position where there are no landmarks to use.
Question 2 (3 marks). Explain why a communication satellite is needed to send a TV signal to a country on the other side of the Earth.
Answer
Radio signals travel in straight lines, and the Earth’s surface curves away. A satellite high above can receive the signal and send it on to the distant country, past the curve.
Question 3 (3 marks). A satellite is 1 500 km above the ground. Calculate the time for a signal to travel up to it. State the assumption.
Answer
Distance = 1 500 000 m. Time = 1 500 000 ÷ 300 000 000 = 0.005 s.
Assumption: the signal travels in a straight line at 3 × 10⁸ m/s.
Question 4 (3 marks). Satellite M takes 1.5 h for one orbit. How many orbits does it make in one day?
Would it suit detailed mapping of a small area? Give a reason.
Answer
24 ÷ 1.5 = 16 orbits.
It suits detailed mapping if its orbit is low, since it is close to the ground and returns often. The short time per orbit suggests a low orbit. The question does not give the height, so the answer is a likely fit, not a certainty.
Question 5 (3 marks). A rocket of mass 200 000 kg has a thrust of 2 600 000 N. Find the weight, the net force and the acceleration.
Answer
Weight = 200 000 × 10 = 2 000 000 N. Net force = 2 600 000 − 2 000 000 = 600 000 N.
Acceleration = 600 000 ÷ 200 000 = 3 m/s². Assumption: the mass is constant at that instant.
Question 6 (3 marks). A satellite estimates the area of clouds over a state as 120 000 km² at 0 h, 150 000 km² at 3 h, 210 000 km² at 6 h and 270 000 km² at 9 h. Find the average rate of growth from 0 h to 9 h.
Answer
Change = 270 000 − 120 000 = 150 000 km². Time = 9 h.
Rate = 150 000 ÷ 9 = 16 667, so about 16 700 km² per hour. The rate is not steady: the cloud grew faster between 3 h and 9 h (20 000 km² per hour) than between 0 h and 3 h (10 000 km² per hour).
Question 7 (3 marks). A satellite records a wetland area of 500 km² in June and 460 km² in December. Find the percentage change.
A student says the wetland was drained. Is that supported?
Answer
Change = 460 − 500 = −40 km². Percentage change = −40 ÷ 500 × 100 = −8%, an 8% fall.
The claim is not supported. The data shows a fall, but it does not show the cause. Drainage, dry weather and seasonal change are all possible, and the table cannot separate them.
Question 8 (4 marks). A farm compares GPS tracking of its tractors (position every 10 seconds, signal lost under dense tree cover) with a paper log filled in every 2 hours. Evaluate the two using only this evidence.
Answer
GPS tracking suits quick location of a tractor: it updates every 10 seconds, against 2 hours (7 200 seconds) for the log, which is 720 times less often.
Limit: the signal is lost under dense tree cover, so the GPS could have gaps there, and the paper log could cover those gaps. The evidence does not say how long the gaps last.
If you got these wrong
Questions 1 to 3 test explaining satellite functions. Questions 4 and 5 test comparing orbit and launch concepts. Questions 6 and 7 test reading space-technology data, and question 8 tests evaluating applications using specified evidence.
Log each slip in the mistake log and paper error review. To work through the gaps with a teacher, see online one-to-one Science tuition.