At first, I tried to answer the problem by taking an average. I added 40, 60 and x together and divided the sum by three. this gave me 60 for x. I thought this was the answer because I saw the word "average" and relied on what previous formulas I'd learn to find the answer.
I didn't answer correctly because I didn't fully take into account both aspects of speed, distance and time. After looking at the diagram a little closer, I realized that I needed to calculate how long the car had traveled and for what length of time before finding the third speed.
The car traveled 20 km at a speed of 40 km/hr, and another 10 km at a speed of 20 km/hr. To go 20 km at 40 km/hr would mean you traveled for half an hour. To go 10 km at 20 km/hr would mean you would have traveled for another half an hour. The question asks what speed you must go to average 40 km/hr. The reason we all answered incorrectly at first was because we viewed speed as a number rather than a measure of distance and time. The formula you would use to figure out the time traveled by each car would be t = v/d.
This problem made me realize that when solving a problem that seems confusing on the surface, most simply require you to step back and look at all the information given before trying to solve.
Tuesday, September 11, 2012
Friday, September 7, 2012
Acceleration and Velocity
http://astronomyonline.org/Science/VelocityAcceleration.asp
This resource clearly and simply goes over the basic principles of velocity and acceleration and makes it easy to understand the difference.
Velocity measures the distance traveled in a particular time frame. The resource gives the formula for velocity as v= d/t (velocity equals distance over time). Velocity only measures constant speeds. Acceleration on the other hand, " is defined as any change in vector ". This means that acceleration measure how how much your speed increases or decreases, or a change in direction.
This resource clearly and simply goes over the basic principles of velocity and acceleration and makes it easy to understand the difference.
Velocity measures the distance traveled in a particular time frame. The resource gives the formula for velocity as v= d/t (velocity equals distance over time). Velocity only measures constant speeds. Acceleration on the other hand, " is defined as any change in vector ". This means that acceleration measure how how much your speed increases or decreases, or a change in direction.
Sunday, September 2, 2012
Hovercraft
Riding the hovercraft was a strange sensation. It felt so strange because most man made forms of transportation such as cars or a skateboard involve friction with the ground. In a hovercraft, however, there are no forces acting on it besides the force enacted on it by the one pushing or stopping it. What this means is that the hovercraft, if pushed, will continue to move until someone provides a force in the opposite direction to stop it.
The heavier the person or the faster the were going, the more force was required to stop the hovercraft. This means that inertia, or the tendency of an object to stay at rest or motion, depends directly on the mass of an object If an object has a net force of zero, it means that it is in a state of equilibrium. Equilibrium therefore implies that there are opposite and equal forces acting on an object.
When pushing the hovercraft, the harder it was pushed, the faster it went and the harder it was to stop the hovercraft. This demonstrates that acceleration depends on force. After the hovercraft was pushed, it remained at a constant speed because there were no forces acting on it to slow it down.When it was time to stop the hovercraft, it was harder to stop the faster the person was going or the heavier they were.
The heavier the person or the faster the were going, the more force was required to stop the hovercraft. This means that inertia, or the tendency of an object to stay at rest or motion, depends directly on the mass of an object If an object has a net force of zero, it means that it is in a state of equilibrium. Equilibrium therefore implies that there are opposite and equal forces acting on an object.
When pushing the hovercraft, the harder it was pushed, the faster it went and the harder it was to stop the hovercraft. This demonstrates that acceleration depends on force. After the hovercraft was pushed, it remained at a constant speed because there were no forces acting on it to slow it down.When it was time to stop the hovercraft, it was harder to stop the faster the person was going or the heavier they were.
Tuesday, August 28, 2012
http://scienceprojectideasforkids.com/wp-content/uploads/2010/10/inertia-2.jpg
This picture is very similar to one of the experiments we did today. In the first picture, both the hoop and coin are at rest. When force is applied to the hoop, the hoop moves but the coin remains in the same spot. Due to Newton's first law of physics, we know that an object at rest stays at rest unless a force is acted upon it, therefore the coin stays at rest.
This picture is very similar to one of the experiments we did today. In the first picture, both the hoop and coin are at rest. When force is applied to the hoop, the hoop moves but the coin remains in the same spot. Due to Newton's first law of physics, we know that an object at rest stays at rest unless a force is acted upon it, therefore the coin stays at rest.
Thursday, August 23, 2012
Physics allows you to understand the world around you. With that in mind, I expect to learn what properties of light allow us to see, what causes the ocean tides, and how airbags keep us safe in cars. The reason I expect to learn these thing is because all of these things involve either interpreting our surroundings or solving problems that our surroundings present to us.
Physics is important because it enables us to understand why things are happening in the world around us, the effect of one event on its surroundings, and to be able to apply science effectively to solve problems in our surroundings. Examples of these would what causes the ocean tides or keeping people safe in cars through the use of airbags.
I want to know what careers physics can be useful in, how physics applies in space, and to understand quantum mechanics.
I want to make an A in the class, be able to use physics beyond the classroom, and to fully understand what I am learning.
Physics is important because it enables us to understand why things are happening in the world around us, the effect of one event on its surroundings, and to be able to apply science effectively to solve problems in our surroundings. Examples of these would what causes the ocean tides or keeping people safe in cars through the use of airbags.
I want to know what careers physics can be useful in, how physics applies in space, and to understand quantum mechanics.
I want to make an A in the class, be able to use physics beyond the classroom, and to fully understand what I am learning.
Subscribe to:
Posts (Atom)