Question

Questions:

1. What is the area of region A?

2. What is the area of region B?

3.What is the area of region C?

4.What is the total area in the three regions?

5. So, what is the speed v1 of the torso as the head begins to accelerate?

KEY IDEA We can calculate the torso speed at any time by finding the area on the torso alt) graph to that time. Calculations We know that the initial torso speed is vo = 0 at time to = 0, at the start of the “collision.” We want the torso speed vi at time ti = 110 ms, which is when the head begins to accelerate. We can find that speed by finding the area under the aſt) curve between those two times: | area between acceleration curve) VI – Vo = 1 I and time axis, from to and t1 ) For convenience, let us separate the area into three regions as shown below: 50 -------- CA 40 100 110 Example 2.7.1 Figure 2

Answer 1

The velocity from acceleration time graph

Area of region A= 0 2 Area of region B = 1 XSox (100-40) ms. AB= 25x 60X10-3 = 1,5 - (3) Area of region = sox (110-100 ms Ac =80x loxio 3 =.soo 9 Acesco A = AA + AR + Ace 2 mis A v, - Vo V=2 mis