 Let's solve a question on identifying period and frequency from a displacement time graph for a simple harmonic oscillator. For this one, a student extends then releases a mass attached to a spring and the graph of the mass's displacement over time is shown below, so we can have the displacement time graph. Here it is. We need to figure out the period and the frequency. Alright, before I get into this, why don't you pause the video and first attempt this one on your own. Alright, hopefully you have given this a shot. Now let's think about period first. What was period to begin with? Period is, we can define period as, we can define period as the time between consecutive or adjacent consecutive maximas or minimas. And for this graph, we can see that the distance between two maximas, we can take this maxima and this maxima right here, not the distance, sorry, the time, this time is, this is six seconds. So period, this is six seconds for this particular type of simple harmonic motion. And frequency, we know frequency is one divided by time, one divided by time period. This would be one by six, one by six hertz. So what frequency really means is that in one second, one second, one by sixth oscillation is being completed. That is what frequency means and it is one by six in this case. Okay, let's look at one more graph. So here it is. Let's remove this. Now let's figure out period and frequency for this graph. Again, period is the time between two consecutive or adjacent to next to next maximas, maximas, this maxima and this maxima or this minima and this minima, the time between these two consecutive minimas or maximas. And for this one, we can see the time is three minus one. This is two seconds. This is two seconds. So period is two seconds for this graph and frequency is one by T, that is one by two, which means 0.5 hertz. That means in one second, 0.5 half oscillation is completed. So if you try to represent the mass attached to a spring for this graph, we can do it like this. We can have this block, this block which is attached to the spring and we can take this point in between. We can take this point as the origin. Everything on the left hand side is the negative and starting from an extreme negative minus three, this would be plus three going up till a positive extreme. This is plus three. So it starts from negative three. And in one second, the situation will look like this. We have the same spring and the block is right here, the block is right here. So this means that half oscillation is completed, full oscillation will be completed when the block is back to its original position at minus three. So this is what the frequency looks like in the case of in the concrete scenario of mass and spring and this graph represents this motion.