Exam-style questions in the shape of Paper 1 and Paper 2, with full markschemes. Read the markscheme, or type, photograph or draw your answer and get it marked.
A fountain jet is modelled, for by
where is the horizontal distance from the nozzle, in metres, and is the height above the ground, in metres. The model passes through the points shown.
| 0 | 3 | 6 | |
|---|---|---|---|
| 1.20 | 4.80 | 5.10 |
Use technology to determine the values of and giving each to at least three significant figures.
Hence determine the horizontal distance(s), in the interval at which the model gives Give your answer to the nearest m.
During an acoustic test, sound level in decibels (dB), is defined by
where is the sound intensity and is a fixed reference intensity. When machines operate together, their sound intensities add.
Machine A alone produces a sound level of dB and machine B alone produces a sound level of dB.
Show that if the sound levels of A and B are and respectively, then
Determine the sound level when A and B operate together. Give your answer to the nearest dB.
Identical copies of machine A are used instead. Determine the least whole number of copies needed for their combined sound level to be at least the level found in part (b).
Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.