I learned a lot about circular motion, gravitation, and centripetal force. I learned that uniform circular motion is when the object is moving at a constant speed in a circle. The velocity is found by 2pi(r)/T. T is the period, or the time it takes for the object to complete one full revolution around the perimeter of the circle it is going in. When an object changes direction, it accelerates. So although the object may have a constant speed, it does not have constant velocity (scalar vs. vector!). The velocity is tangential, and the acceleration of the velocity is called centripetal acceleration. This is found by the equation v^2/r. The acceleration is perpendicular to the velocity. The force that keeps the object going in a circle is called centripetal force. This force is found by using mv^2/r. There are also vertical circles. These circles are not much different, accept for at the top you subtract mg and when it is at the bottom you add mg. Universal Gravitation states that the force that pulls all other bodies and causes them to fall exists also between all other bodies. This force pulls down, but also things together. This helps things like the planets stay in orbit.
What I have found difficult is knowing what equation to use at what time; especially with the gravitational equations. I also find the FBD's difficult to draw, because the forces can be switched around. I also sometimes get confused what the system is. I am still getting the hang of gravitational forces, but i think i am getting better. Practice makes perfect.
I think that my problem solving skills are pretty good, but could definitely improve. I think that with the more problems that I see, I improve with each one. I sort of freak out when I glance at a problem and it seems too difficult. But when I actually look at it and focus I usually see a way to find the answer. I think my problem solving skills are definitely improving.
Wednesday, January 27, 2010
Sunday, January 10, 2010
Newton's Second Law part A
I learned how to do many things after learning Newton's second law. Newton's second law states, "for a particular force, the acceleration of an object is proportional to the net force and inversely proportional to the mass of the object." This law links mass, acceleration, and the forces. This can be used with many problems, and even systems. Systems don't usually balance out, and this law helps find the acceleration. This law uses the formula a=∑F/m or ∑F=ma. Using this formula I learned to solve problems with acceleration in them, not just problems at constant speed or at rest. I also found out how to solve systems, including problems using pulleys and Atwood's machines. With these problems I improved my ability to draw FBD's and calculate the sum of the forces. I have also learned how to calculate the friction force acting on an object. The equation for this is Ff= Fn(mu). mu is the coefficient of friction and is used to calculate the frictional force.
What I have found difficult with this law and these problems is when I do not have much information, and I have to keep working on the problem and it somehow works out in the end. I get a little confused going through the problems without knowing multiple variables. Also, a am not quite a master at finding the mu and friction force, because we just learned about it and it is still fairly new.
I think my problem solving skills are improving and I am able to catch on to new ideas faster. Although I am not a master at the frictional force equation and problems yet, I am catching on to this idea much faster and already understand it with most problems. I sometimes find certain acceleration problems difficult when not much information is given. I am fairly secure with systems, and can usually find the answers that I am looking for. Overall I think I am getting better at solving problems and can grasp ideas quicker.
What I have found difficult with this law and these problems is when I do not have much information, and I have to keep working on the problem and it somehow works out in the end. I get a little confused going through the problems without knowing multiple variables. Also, a am not quite a master at finding the mu and friction force, because we just learned about it and it is still fairly new.
I think my problem solving skills are improving and I am able to catch on to new ideas faster. Although I am not a master at the frictional force equation and problems yet, I am catching on to this idea much faster and already understand it with most problems. I sometimes find certain acceleration problems difficult when not much information is given. I am fairly secure with systems, and can usually find the answers that I am looking for. Overall I think I am getting better at solving problems and can grasp ideas quicker.
Monday, December 7, 2009
Part A:
This is what i learned about Newton's first law of motion. Newton's first law states that "an object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force." This law pertains to translational equilibrium. This means that the sum of the forces on the x axis and the sum of the forces on the y axis add up to zero. If the object is at rest or at a constant speed than it is at translational equilibrium. This simple knowledge helps to solve many problems, with the help of a little algebra. To solve these problems i learned how to draw free body diagrams (FBDs). These diagrams show all the different forces acting on an object and help me better understand the problem and what it is asking. I have also learned about rotational equilibrium. This has to do with rotations and torque. It adds the sum of the torque forces to the problems. The sum of the torque forces also add up to zero when it is in rotational equilibrium.
What i have found difficult about what we are studying is when the objet is on an inclined plane. This gives me trouble, especially when i have to switch the SIN and COS on theta. Also, the algebra sometimes gives me a little difficulty, especially when i do not take my time. I tend to be over- confident in the algebra, and go way too fast. I make small mistakes which ultimately lead to me getting a totally wrong answer. Last, the rotational equilibrium confuses me greatly. I am still new to this topic, and still do not fully understand the concept. The FBDs are fairly easy but finding the answer is still a bit confusing to me.
My problem solving skills are pretty good i would say. I think they could be a lot better if I would slow down and take problems one step at a time. I think if I would look over my equations before i try to solve problems, that would help me not to confuse them. I also think that if I checked over my work more I could catch small careless mistakes. Also, I believe if I would do a few more problems over the concepts that confuse me more often that i would grasp the overall concept better and be able to solve more problems. Overall, my problem solving skills are pretty good, but i have a few small issues with solving problems sometimes.
Part B:
There is a big connection between Newton's first law and everyday life. This law and forces are found everywhere! For example, a bridge over a body of water has to have beams to keep it up. These beams have to be able to withstand so much force, and that can be determined by this law. If the beams could hold up the bridge but not he cars, then the bridge would fall and many people would die. Second, a stoplight i s a great example of tension. The wires holding the light up have to be strong enough to hold up the light and not fall or break. If we did not know how to calculate these things, many bad things could happen. Physics and Newton's first law ( Translational and Rotational equilibriums) help not only architects, scientists, designers, and inventors; but they help everyone!
This is what i learned about Newton's first law of motion. Newton's first law states that "an object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force." This law pertains to translational equilibrium. This means that the sum of the forces on the x axis and the sum of the forces on the y axis add up to zero. If the object is at rest or at a constant speed than it is at translational equilibrium. This simple knowledge helps to solve many problems, with the help of a little algebra. To solve these problems i learned how to draw free body diagrams (FBDs). These diagrams show all the different forces acting on an object and help me better understand the problem and what it is asking. I have also learned about rotational equilibrium. This has to do with rotations and torque. It adds the sum of the torque forces to the problems. The sum of the torque forces also add up to zero when it is in rotational equilibrium.
What i have found difficult about what we are studying is when the objet is on an inclined plane. This gives me trouble, especially when i have to switch the SIN and COS on theta. Also, the algebra sometimes gives me a little difficulty, especially when i do not take my time. I tend to be over- confident in the algebra, and go way too fast. I make small mistakes which ultimately lead to me getting a totally wrong answer. Last, the rotational equilibrium confuses me greatly. I am still new to this topic, and still do not fully understand the concept. The FBDs are fairly easy but finding the answer is still a bit confusing to me.
My problem solving skills are pretty good i would say. I think they could be a lot better if I would slow down and take problems one step at a time. I think if I would look over my equations before i try to solve problems, that would help me not to confuse them. I also think that if I checked over my work more I could catch small careless mistakes. Also, I believe if I would do a few more problems over the concepts that confuse me more often that i would grasp the overall concept better and be able to solve more problems. Overall, my problem solving skills are pretty good, but i have a few small issues with solving problems sometimes.
Part B:
There is a big connection between Newton's first law and everyday life. This law and forces are found everywhere! For example, a bridge over a body of water has to have beams to keep it up. These beams have to be able to withstand so much force, and that can be determined by this law. If the beams could hold up the bridge but not he cars, then the bridge would fall and many people would die. Second, a stoplight i s a great example of tension. The wires holding the light up have to be strong enough to hold up the light and not fall or break. If we did not know how to calculate these things, many bad things could happen. Physics and Newton's first law ( Translational and Rotational equilibriums) help not only architects, scientists, designers, and inventors; but they help everyone!
Thursday, November 12, 2009
Wednesday, November 11, 2009
My crossword!
try testing yourself!
3. if one object is fired directly horizontal while the other is dropped from the same height, they will hit the ground at the ______ time. (neglecting air resistance)
4. the sign for horizontal velocity
5. the factor that is always constant
7. what you use to find the vertical component of the velocity (initial)
8. the horizontal distance the object travels
9. gravity causes the vertical component of the velocity to ________.
10. the sign for initial velocity
11. the object that is in motion
12. the component of the velocity that remains constant the whole time
Down
1. what you use to find the horizontal part of the velocity (initial)
2. how far off the ground the object is (at a given time or at the peak of its flight)
4. the component of the velocity that accelerates constantly due to gravity
6. the sign for vertical velocity
Across
3. if one object is fired directly horizontal while the other is dropped from the same height, they will hit the ground at the ______ time. (neglecting air resistance)
4. the sign for horizontal velocity
5. the factor that is always constant
7. what you use to find the vertical component of the velocity (initial)
8. the horizontal distance the object travels
9. gravity causes the vertical component of the velocity to ________.
10. the sign for initial velocity
11. the object that is in motion
12. the component of the velocity that remains constant the whole time
Down
1. what you use to find the horizontal part of the velocity (initial)
2. how far off the ground the object is (at a given time or at the peak of its flight)
4. the component of the velocity that accelerates constantly due to gravity
6. the sign for vertical velocity
My new Glogster!!
I made a glogster and hope i post this right... Click here to view my horizontal projectile motion glogster.
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