The mass, $m$ mg, of a radioactive substance decreases with time, $t$ hours. It is known that&nb

Question

The mass, $m$ mg, of a radioactive substance decreases with time, $t$ hours. It is known that $m$ and $t$ are related by the equation $m = Me^{-kt}$, where $M$ and $k$ are constants. The table below shows measured values of $m$ and $t$. $t$ (hours)$1$$2$$3$$4$$5$ $m$ (mg)$6.55$$5.36$$4.40$$3.60$$2.94$ Plot $\ln m$ against $t$ and draw a straight line graph.[2] Use your graph to estimate the initial mass of the substance[2] the value of k [2]

Accepted Answer

(b)M = 8.00 (c)k = 0.2

2025 DSS PRELIMS P1 Q13

2025 DSS PRELIMS P1 Q13