00:01
Our first question, 58, is that a material is said to be blank if it changes shape when there's a deforming force and then returns to its original shape when you remove the force.
00:11
So some of our options, we know that stretchy is not really a scientific term.
00:15
This definitely isn't rigid because it's not holding its shape the whole time.
00:19
It's not plastic.
00:21
So if our options are elastic or inelastic, if you think of a rubber band, when you stretch it out, it stretches back.
00:27
So this is an elastic force.
00:36
Now hooke's law relates.
00:38
So for hooke's law we have force is equal to a constant dependent on material to the distance stretched.
01:08
So if we look at our answers, we can see that hooke's law relates the distance of a spring to the force of fall.
01:26
Now if the length of a cube is doubled.
01:34
What happens to the cube surface area? surface area is 6 times a squared.
01:44
So let's use an example.
01:46
Let's say l1 is equal to 1 and l2 is equal to 2.
01:50
So if a1 is equal to 6 times 1 squared so 6.
01:57
Whereas a 2 is equal to 6 times 2 squared which is 24.
02:06
And if we do the ratio 24 over 6 is equal to 4...