**Impact force**

Created by prof Hwang Modified by Ahmed

Original project Impact force

Two objects with m1 and m2 respectively, released from the same height

**h**to the ground.

Under the condition: mass m2=2*m1

The time for object to reach the ground are T1 and T2 respectively,

Normally, the air reststance can be ignored for heavy objects, and we know that

T2=T1=, where g is the gravity.

If the impact forces are F1 and F2 respectively.

What is the relation between F1 and F2?

A. F2>2*F1

B. F2=2*F1

C. F2<2*F1

The impact force F=△P/△T, where △P is the momentum change during the impact and △T is the impact time.

Both object drop from the same height, so the velocity when impact start is ,

So △P2=2*△P1.

We need to know the relation between △T2, △T1 in order to compare F2/F1.

If △T2= △T1, then F2=2*F1.

However, is it true that △T2= △T1

If △T2> △T1 , how to find out relation between F1 and F2?

You can check out the answer with the following simulation:

The impact time △T and Faverege will be shown. F(t) is available, too!

The impact force is modeled with.

**Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop.**This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

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