Aussie Maths & Science Teachers: Save your time with SmarterEd
The braking distance of a car, in metres, is directly proportional to the square of its speed in km/h, and can be represented by the equation
where
The braking distance for a car travelling at 50 km/h is 20 m.
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Moses finds that for a Froghead eel, its mass is directly proportional to the square of its length.
An eel of this species has a length of 72 cm and a mass of 8250 grams.
What is the expected length of a Froghead eel with a mass of 10.2 kg? Give your answer to one decimal place. (3 marks)
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The height above the ground, in metres, of a person’s eyes varies directly with the square of the distance, in kilometres, that the person can see to the horizon.
A person whose eyes are 1.6 m above the ground can see 4.5 km out to sea.
How high above the ground, in metres, would a person’s eyes need to be to see an island that is 15 km out to sea? Give your answer correct to one decimal place. (3 marks)
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