A student is modelling the decay of a radioactive source using the equation
ΔNΔt=−0.4N \frac{\Delta N}{\Delta t} = -0.4 N ΔtΔN=−0.4NThe student decides to use Δt=0.20 s\Delta t = 0.20\text{ s}Δt=0.20 s. The number N N\,N of radioactive nuclei is 5000 at t=0t = 0t=0.
Part of the modelling spreadsheet from the student is shown below.
| t / st \text{ / s}t / s | Number N N\,N of radioactive nuclei remaining at time ttt | Number of nuclei decaying in the next 0.20 s |
|---|---|---|
| 0 | 5000 | 400 |
| 0.20 | 4600 | |
| 0.40 | ||
| 0.60 |
What is the value of N N\,N at t=0.60 st = 0.60\text{ s}t=0.60 s?
3800
3893
4232
4600
90 exam-style questions on OCR A A Level Physics Nuclear and particle physics, covering The nuclear atom, Fundamental particles, Radioactivity, and Nuclear fission and fusion. Each one has a worked solution and a mark scheme showing where the marks go.