This following applet is

**Impact force**Created by prof Hwang Modified by Ahmed

Original project

Impact forceTwo 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=$sqrt{2h/g}$, 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 $v=sqrt{2gh}$,

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$ F(y)=-k*(y-y_0)-b*v_y$.

Full screen applet or

Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list**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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