00:01
In this problem of motion along a straight line we have given that an ice boat has a constant velocity towards the east when a sudden gust of wind causes the ice to have a constant acceleration towards east.
00:17
So let's suppose this is the boat and this is moving towards east.
00:21
When a sudden gust of wind appears it has to accelerate that means wind is applying certain force on that boat.
00:30
For a period of 3 seconds and acceleration is for 3 seconds and a plot of x versus time t is shown i'm showing you so this is the figure for that where t is equal to 0 say this is is time t is equal to 0 is taken to be instant the wind instant the wind starts to blow and positive x x x xx towards the east so this is the positive x xx towards the east we have to find what is the acceleration of iceboat during 3 second interval? so we have to find the acceleration of the iceboat during 3 seconds of interval.
01:13
So we have to pick 2 points on this graph.
01:16
So let's suppose the first point is say t is equal to 2 seconds, say this is t is equal to 2 seconds and position it as say this is 16 meters and t is equal to 3 second this is at this is 27 meters and now we have to apply the formula that is x1 is equal to or we can say this is x is equal to this is a constant velocity so this is v0 multiplied with t plus half and acceleration and t square now x1 putting the value x1 which is equals to 16 so v0 is constant so v0 and t is equal to 2 plus half and acceleration is a and t is equal to 2 square say this is equation number 1.
02:01
And x1 is equals to here 16 now putting the value second say this value would be 27 and v0 multiplied with 3 plus half acceleration and this is 3 square so this is equation number 2 now by solving first and second we get initial velocity is equals to 6 .0 meters per second and acceleration comes to be 2 .0 meters per second square so this is the answer of a part a that is acceleration is equal to 2 meters per second square.
02:39
Now part b, part b says what is the velocity of iceboat at the end of 3 seconds...