00:01
Here we look at an example of newton's second law of motion in one dimension.
00:08
So the direction that we're going to focus on is the y direction, and i will call upwards positive.
00:19
So newton's second law says that the sum of vector forces acting on its, in an object, is equal to its mass times its acceleration.
00:31
And sometimes that sum of forces is called the net force.
00:37
Now, since we're in one dimension, we only have to worry about one direction.
00:44
And so we can simplify this down to the net forces in the y direction is equal to the mass of the object times the acceleration in the y.
00:58
Our question is, what is the acceleration in the y direction? for some object.
01:04
Here i've made it a rocket with a mass of two kilograms, and we know that there is a force applied to it of 25 newtons upwards.
01:17
So what you would like to do is to draw a force diagram, and you want to show all the forces potentially acting on that object.
01:29
Well, there's the one that was given to us, and we're going to show that acting on a point, mass, we can often forget about the details of the object by treating it like a point mass, and that's usually good enough for our situation.
01:50
But there's 25 newton's acting up as an applied push.
01:57
We'll just call that applied.
02:00
And we also know you can't get rid of the object's weight, and we're assuming that it's up in the air so that all of its weight is unsupported by anything underneath...