Unit 1 Summary


In this unit we started off by learning about Inertia and Newton's First Law of Motion. Newton's First Law states, "an object in motion or an object at rest will stay in motion or at rest until acted upon by an outside force". An example that I always think of when I hear that law is the famous trick of puling a table cloth from out from under a set table.

Inertia means nothing in the universe will move on its own.Inertia is not a force. Have you ever wondered why when you shake a bottle of ketchup and then stop the ketchup comes out? When you are shaking the bottle and bring the bottom down and suddenly stop it inertia is happening. It is what causes the ketchup to come out of the bottle.


We then moved on to learning about net force and equilibrium. Net force is the overall force acting upon an object. To calculate the net force you add the amount of each force acting on the object together. Force is measured  in a unit called a newton. Whenever an object has a net force of zero it is at equilibrium.
If 18 newtons of force are applied to the left and -20 newtons of force applied to the right, and you add the two, the net force will equal -2 newtons. The object is not at equilibrium.


Moving on we then explored velocity. Velocity is the measurement of a specific amount of distance traveled in a specific amount of time. The absolute value of velocity is called "speed". The change in velocity occurs when an object changes direction by either speeding up, slowing down, or turning. The formula used to find velocity is v=at. We measure velocity in units meters per second.

Constant Velocity is when an object travels for the same distance at the same time. An object can not change direction or be accelerating when it is at constant velocity. There are two equation we use when dealing with constant velocity. When trying to calculate how fast an object is going we use v=d/t. To calculate how far an object has gone we use d=vt.

How far did a car go that traveled at a constant speed of 300 meters per second north for 60 seconds?

 Since we know the speed is at constant velocity and the question is asking how we know to use d=vt. 
d=? v=300 m/s t=60 seconds
d=300(60)
d=18000 meters The car traveled 18000 meters at a speed of 300 m/s for 60 seconds. 


Following velocity we talked about acceleration. Acceleration is the increase or decrease in the rate of an object. Acceleration=the change in velocity/time interval. a=change in v/t. The change in velocity is found by finding the difference in the initial velocity and the end velocity. Acceleration is speeding up, slowing down, and changing direction, all of which change velocity. Constant acceleration means an object is constantly changing velocity. There are also two equations we use for constant acceleration. 
When we are calculating how fast an object is going at constant acceleration we use v=at.
When calculating how far an object has gone during constant acceleration we use d=1/2at.


The final subject we touched on taught me how to use a graph. Y=mx+b is the equation for a straight line. 
y=mx
Distance=y
Time=x
d=vt 
m=v
distance=velocity(time) 

When graphing constant acceleration you need a moving trend line rather than a linear because the slope is changing as the time increases. 

 Today in physics my class rode a hovercraft. In this lab we experience the first hand of inertia and Newton's First Law of Motion up close and personal.

A. Riding a hovercraft feels like you are riding a sled in the air (the plastic disk sleds). I would say to expect to feel like you are just floating through air. The difference between riding on a sled, skateboard, etc, and riding a hovercraft is that there is no friction with the hovercraft like there is in other transportation.

B. By seeing the hovercraft in action I now have a better understanding of Inertia. Inertia means an object will stay in motion until an outside force interrupts it. Net force is the overall force acting on an object. It is measured by adding up all the forces on an object together and if the sum is zero then it has reached equilibrium.

C. Acceleration seems to depend on the strength of the outside force.

D. Based off this lab I expect to have constant velocity when the hovercraft is in phase two and is moving with out the the act of an outside force upon it.

E. Different members who rode the hovercraft were harder or easier to stop because weight and mass came in to effect here.

                                       




Nothing in the universe will move without the help from an outside force. That statement is supported by Newton's First Law, "an object in motion or an object in rest will remain in motion or in rest unless acted on by an outside force". An easier term to help explain this law is known as "Inertia". Inertia simply means, "nothing will move on it's own".