Ch+4+Sec+2+KirnumB

Section 2

What do you see? The cart on a steeper slope seems to be enjoying the roller coaster then the one with the smaller slope

What do you think? The steel roller coster will give a bigger thrill. It has a much steeper hill and will cause the fastest acceleration, thus providing the bigger thrill.


 * Physics Talk**
 * The speed of a ball at the bottom of a track is determined not by the length of the incline but the initial height of the ball
 * KE and GPE depend on the mass of the ball
 * GPE decreases as the ball comes down the incline because the height is decreasing
 * KE increases

1. Changing the length of the incline doesn't change the speed of the ball; only changing the balls height will change its speed
 * Checking Up**

2. GPE of an object changes with its hight because the distance changes. When you change the mass, you change the acceleration

3. When a ball has more mass and more speed, it has a greater KE

4. It is put into KE

5.30,000

1. They are the same
 * PTG**

3. Mass=200 kg g=10
 * **Position of Car-> Height (m)** || **GPE (J)=mgh** || **KE (J)=.5(mv^2)** || **GPE+KE (J)** ||
 * top (30 m) || 60,000 || 0 || 60,000 ||
 * Bottom (0m) || 0 || 60,000 || 60,000 ||
 * Halfway (15 m) || 30,000 || 30,000 || 60,000 ||
 * 3/4 way down (7.5m) || 15,000 || 45,000 || 60,000 ||

4

**GPE** **KE**

5) Mass-300kg
 * **Position of Car-> Height (m)** || **GPE (J)=mgh** || **KE (J)=.5(mv^2)** || **GPE+KE (J)** ||
 * top (25 m) || 75,000 || 0 || 75,000 ||
 * Bottom (0m) || 0 || 75,000 || 75,000 ||
 * Halfway (12.5 m) || 37,500 || 37,500 || 75,000 ||
 * 3/4 way down (5m) || 15,000 || 60,000 || 75,000 ||

6)

 **GPE**  **KE**

7) a. b. c. At the middle

8. It wouldn't change. mgh=1/2mv^2 and masses cancel.

9. a) It is traveling fastest at B because it has the lowest height b) C and F; they have the same height c) D; it is lower

10b) There is no KE left and there isn't enough speed to get up the second hill. 11) m=200
 * **Position of Car-> Height (m)** || **GPE (J)=mgh** || **KE (J)=.5(mv^2)** || **GPE+KE (J)** ||
 * top (0 m) || 0 || 50000 || 50000 ||
 * Bottom (25m) || 50000 || 0 || 50000 ||
 * Halfway (15 m) || 30000 || 20000 || 50000 ||
 * 3/4 way down (0m) || 0 || 50000 || 50000 ||

What do you think now? The two tracks will be the same speed because they start at the same height. B will provide a greater thrill because it accelerates faster