Hello! This week the big question for our lab was to find the relationship between force, mass and acceleration. We did this by using a cart attached to a fan (like the ones you can find in Louisiana or Florida except on a much smaller scale) along with a force probe attached to a metal ring in order to calculate force and various brass masses.
We started the lab by finding the mass of the empty cart (.3kg) and then we measured the force by allowing the fan cart to push against the metal ring. Graphing this on our computer, we found the average force of the fan cart. Throughout the lab the force generally remained constant because the fan worked the same regardless of the mass on the cart as long as it was charged . Finally, we found the acceleration of the fan cart by allowing the cart to accelerate into and hit the metal ring from a distance. We used the slope of the line in our graph before the collision took place as our acceleration. We repeated these steps 5 more times with various masses added to the original weight of the cart.
We noticed a pattern after calculating our data. First, as I said before, the force of the fan cart generally remained the same (around .2N) no matter what weight was applied. Second, the acceleration of the fan cart increased as the mass of the fan cart decreased. This means that acceleration and mass are inversely proportional. The fan cart that weighed the least (with no added mass) had the highest acceleraration (.6231 m/s/s) while the fan cart with the highest mass had the lowest accelerarion (.1933 m/s/s)
Through this, we discovered A NEW FORMULA!!!!! A=F/m or F=mA
What I learned from both the fan cart and disk lab:
If something is moving, it will keep going until a force acts on it
FRICTION changes an object's state of motion (will learn more about it next week)
-Even with a perfectly smooth floor that is 5 miles long, air molecules will create resistance (friction) and slow the disk down
-A free body diagram shows all forces (magnitude and direction) on one object
-For every interaction there are two equal but opposite forces of the SAME TYPE (gravitational, normal, friction)
SOMETHING AT REST=SOMETHING AT CONSTANT SPEED (Real world example: bullet train, plane or elevator. When at constant speed, you feel as if you might not be moving at all. The only time that you can feel the motion is when the train/ elevator/plane is slowing down,speeding up, starting, or stopping)
According to Newton, there is no such thing as motion. Motion is not real. There is no way of calculating it.With respect to the earth, I am not moving but with respect to the sun, I am moving 65,000 mph. Seems crazy right? Only acceleration is real.
NEWTONS LAWS OF MOTION:
1st Law: If an object is at rest or constant speed, it will remain that way unless it expiriences a net (unbalanced) force. A net force is required to accelerate an object.
2nd Law:The amount that an object accelerates depends on the objects mass and the force that it expiriences. We saw this in our lab. If the objects has more mass, then will not accelerate as much as an object with a smaller mass (F=ma)
3rd Law: When objects interact, eac exherta force on one another that is EQUAL but OPPOSITE
The force that the object feels is
-the same type of force
-the same amount/magnitude of force
-the opposite direction of the force that the other object feels
REAL WORLD CONNECTION:
Let's say that someone gets hit by a car :( They both feel the same amount of force but in opposite directions. Since the car has more mass than the person, the car will not move a considerable amount due to the collision. The person, however, will unfortunately go flying because he or she had less mass than the car.
