 So this is the seventh question. It says calculate the acceleration of a body which starts from rest. This is the important information. Starts from rest and travels 87.5 meters. So this is check the units SI unit fair enough and in five seconds. So in is missing here in five seconds. Okay. So calculate the acceleration of a body which starts from rest. So hence let's write down what is given. So basically you have to find out acceleration. So this is not known and starts from rest. That means initial velocity. Initial velocity of the object is is equal to you is equal to zero. Okay. So it's always good to draw a representative diagram. So let us draw a diagram. So here is the that's it. This is that straight line in which the body is moving. Let's say it starts from A goes to B. Okay. And says that travels 87.5 meter in five seconds. So let's say we start from T equals to zero and T is equal to five is the window I am talking about here. What information is given you is zero and here V is unknown. Not known. So put a question mark. Acceleration is also unknown. But this distance s this distance s is known. It's given how much is it s is clearly given here. See 87.5 meters and it is an SI unit. So this is what I would be taking care of while solving. Now let's go back to our calculation. So initial velocity is zero and T is equal to five seconds. So write five seconds and s is equal to how much 87.5 meters. Now how do we approach this? So one way most of students do is they first write down the three equations. So V is equal to U plus 80 is the first equation of motion. Second one is s is equal to U T plus half A T squared. And the third one is V squared is equal to U squared plus twice A s. Isn't it? So this is what are the three things and and we have already always been taught that okay find out where all data is given. So if you check this is a very simple case that s is participating in these two. So obviously one of these could be handy but here V is not known. So hence you can eliminate this equation. So what is left? This one. So let's try that one. So s is equal to U T plus half A T squared is the equation to be used here. It may not be that straightforward every time but here in this case it's very very simple. So you can always use that approach. But if let's say there is more intricacies involved so you have to break down the problem into multiple parts and apply these motion equation individually. We'll take those kind of problems also. Not now. Okay so now it is fair enough. Very very simple 87.5 deploy the values. Usually I suggest that before you deploy the values simplify the equation itself. So U is zero. So hence this is Vaf A T squared. U is zero no? So this item is zero. So hence s is half A T squared. So from here what will happen? So ignoring it for the time being. So A is to be found out. So A is nothing but twice s divided by T squared. Isn't it simple? Two times s divided by T squared. And now very easy deploy the values. In the last step you should deploy the values to eliminate as many errors, calculation errors as possible. I have seen a lot many of you do lots of calculation errors. So hence till the last step try to deal with variables. And in the last step now you deploy the values. What is 5? 5 squared. So hence if you see this is nothing but 175 am I right? Yeah 175. Okay divided by 25. And this is nothing but 7. 7 right 25 7s are 175. But you have to also give the units. Always remember this is error zone. Okay error zone where you don't write the unit. So units will be in SI units. Right? So 7 meter per second square. Right? So always note error zone. What is error zone? Forgetting units in physics is dangerous. Do not forget to write units. Right? So in physics units are like soul of the entire problems. You don't write unit. It's meaningless. Right? So only 7 means nothing. 7 kilo, 7 meter, 7 seconds. What? So hence meter per second square is the acceleration. Since everything was in SI units, everything was in SI units. So acceleration will also come out in SI units. Okay? So hence remember this. Another learning is write or deal in variables. Take it to the last step where now you know no more simplification could be possible. Then you deploy the value of the variables and calculate it. This will eliminate some of your calculation errors. Now let's say if you start doing here itself, this step self you deploy values and end up doing the wrong calculation, then the error will percolate down and that's not good. Okay? So hope you understood how to solve this problem. Thank you.