## Units in 15.29

$\frac{d[R]}{dt}=-k[R]; \ln [R]=-kt + \ln [R]_{0}; t_{\frac{1}{2}}=\frac{0.693}{k}$

Posts: 62
Joined: Thu Jul 27, 2017 3:01 am

### Units in 15.29

I thought that it was standard to change your units from whatever unit of time to seconds. Why did the book express the answers in terms of minutes? And how do we know when to switch up the units or to let them stay the same?

Nickolas Manipud 1C
Posts: 60
Joined: Fri Sep 29, 2017 7:07 am

### Re: Units in 15.29

It might have been because the question gives you minutes. You're right to say that it is usually standard to use seconds. On the test, I'm sure that you'll still get credit if you use either seconds or minutes unless the question wants a specfic unit.

Gurshaan Nagra 2F
Posts: 49
Joined: Thu Jul 27, 2017 3:01 am

### Re: Units in 15.29

I think it is fine to leave the time units in terms of what the question gives you, unless they explicitly ask it for something else