Unit 3 Blog Reflection

This unit we learned a lot of new material. We started the unit off learning about vectors and calculating what direction an object is going to travel in if it has two different forces acting on it. We learned that you would dray two lines that represent the two different forces and one line that bisects your starting two lines that represents what direction the object is going to move in. With our new knowledge of vectors we learned the physics relating to why a box on a ramp slides down the ramp. After vectors we moved onto the universal gravitational force which is F=G(M1)(M2)÷d². This formula can be used to find out the weight of someone or something. The force that you have on the surface of the Earth is different then the force that you are going to have on a large mountain. This is because force is inversely proportional to distance. If the distance is further rather then shorter then the force is going to be lesser. If the distance is going to be shorter rather then shorter then the distance is going to be greater. On the other hand, force is directly proportional to mass, the greater the mass the greater the amount of force, the smaller the mass is the lesser the amount of force. Next we talked about tides. Tides are caused because of the difference in force felt by opposite sides of the Earth. The two opposite sides of the Earth, although they are experiencing different forces, are experiencing the same tides. When the moon is in a new or full state spring tides occur. During spring tides the highs are higher then normal and the lows are lower then normal. On the contrary, when the moon is waxing or waning, the lows and highs are regular. After tides we moved on to momentum. Momentum is inertia I motion. Momentum = massXvelocity. (p=mv) Along with momentum we learned about impulse. Impluse is represented with the letter j. J=the change in p and J = f∆t. The impulse is the same regardless of the amounts of force and time. The only difference is with the amount of time and the amount of force. The longer it takes for the change in momentum or impulse to complete the lesser the force is going to be. The shorter it takes for the impulse to complete the greater the amount the force is going to be. This is why gymnasts use mats. The mats extend the time of impulse so the force exerted on their feet is less. Without the mats the time of impulse is going to be smaller and the force on the gymnasts feet is going to be larger, because of the greater force the gymnasts risk injury. Next we worked with colliding objects. When one object is moving and runs into another object and then forces that one to move or when two objects are moving toward each other we used the formula M_AV_A-M_BV_B=(M_A+M_B)V_AB. Using this formula we are able to solve for V_AB which will tell us the velocity that the whole system is moving with after the collision. We then asked how it was possible for a ball that is moving with a horizontal velocity to hit a ball that is still and cause it to move in the vertical direction. This is possible because the forces are equal and opposite, so the vertical forces created are going to add up and equal to zero!  

Unit 3 Picture

This picture is an example of tides. Tides are caused because of the difference in force felt by opposite sides of the Earth. The tides that come in and out of this rocky area are going to occur every six hours. If this were a low tide right now, in six hours there would be a high tide and six hours after that would be low tide again. If this was a low tide, then the opposite side of the Earth is also going to be experiencing low tides, the same goes for high tides. If the moon were a full moon or a new moon, the high and low tides would be more dramatic. These are called spring tides. The less dramatic tides that occur during waxing and waning moons are called neap tides.