Unit 1
Forces of motion
Motion: Motion will occur if an object changes position.
Speed: Speed is a way people measure motion. The formula for measuring speed is S=D/T that is Speed= Distance/Time Velocity: Velocity is very similar, but is still different to speed since velocity is the speed of an object plus the direction. Acceleration: Acceleration is a way to measure the change in motion of an object since not all objects stay at a constant speed. Acceleration only appears when there is a change in speed positively or negatively, and when there is a change in direction. So, it occurs when there is a change in velocity. The formula for acceleration is A= vf - vo t that stands for final velocity - initial velocity over time. Balanced and unbalanced forces: A force is balanced when there is the same amount of force pushing from each side. And, unbalanced forces are forces when one side is pushing or pulling with more force than the other side and that will make the object move. We even did a experiment will this with a game of tug of war and when nobody was moving they were pulling with the same force and when one team started winning they were pulling with more force. Newtons: The amount of force exerted on objects are measured in Newtons so for example 15n and etc. This was made by Sir Issac Newton that is why the measurement is called newtons since it was invented by him. Friction is a force that resists motion. Friction: Friction is affected by how hard two surfaces push against each other. And its affected by the molecules in each surface. Static friction is one kind of friction that occurs when you or an object is not moving. And, this is why its so hard to move an object when you first pick it up or etc. There is also sliding friction and this occurs when you slide an object over another this is why its easier to move and object once its moving. Fluid friction this happens when a object moves through a fluid for example when someone is swimming they are being affected by fluid friction. Rolling friction this happens when an object rolls on or across a surface for example would be a bolder rolling down a mountain. Gravity: Gravity is a force that pulls an object towards another object, and gravity is always affecting us even now since Earths gravity is what keeps us from floating away into outer-space. Things that affect gravity are mass and distance these affect gravity in the following ways. Well, the more mass an object has the more gravity it has. And also the greater distance there is between two objects the less gravity their is and the less distance between two objects then the more gravity there is between them. Also, weight is dependent on the amount of force there is so on the moon you would weigh less than you would on earth since earth has more gravity. The formula is W=mg Weight = mass * gravity. Sir Issac Newton and his three laws: His first law is an object in motion stays in motion and an object at rest stays at rest. What that means is that when an object is moving it will keep on moving this is called inertia. A example of this is if you get in a car accident and you were not wearing a seat belt. You will then go flying threw the glass, and on to the road this is an example of inertia since you were in motion and you didn't stop since an object in motion stays in motion and an a object at rest stays at rest. Newtons second law is in the present of a net force, there is an equal and opposite reaction. For his third law it is for every action there is an equal and opposite reaction. |