00:02
Hi, here in this question we are given that a force of 40 newton is applied to a string and it is stretched to x equals to point two.
00:20
Now using hook below first we will find the value of k k equals to f upon x.
00:25
Therefore here in our case we have k equals to 40 divided by point two which is again equal to 200 newton meter.
00:33
Now, we need to find the work done, therefore work done equals to del u here, del u would be 1 by 2 k x f squared minus x i squared.
00:47
Here in our case, the string was stretched from initially it was at, therefore x i equals to 0 .1 centimeter and it was stretched up to x f equals to 0 .3.
01:02
Therefore, here in our case, we have w equals to 1 by 2, k which is 200 times 0 .3 square minus 0 .1 square.
01:13
Therefore, on simplifying this, here we have work equals to 8 jule.
01:22
Thus, we got our first answer as the work turn is equal to 8 jule.
01:34
Now, moving towards the second part of a question, which is here we are given that a mass of an object is 500 kg and now here we are given that force equals to 500 g that g is nothing but 9 .8.
01:57
Now on simplifying this here we have force equals to 4 ,900 newton.
02:03
Now here we are given that x is equal to 4 cm therefore it can be written as 0 .04 meter.
02:10
Therefore, using hucklow, the value of k would be f divided by x, which is again equal to 4 ,900 divided by 0 .04, which is again equal to 1 -2 -5 -0 -0 -newton meter.
02:28
Now, we know that formula to find work is 1 by 2 kx squared...