# Pressure problem - Impulse of object striking a head

1. May 5, 2014

### ron360

Pressure problem -- Impulse of object striking a head

1. A police crime lab is trying to determine whether someone was murdered or died as a result of an accident. He was struck in the temple by a 4.20 kg sculpture that is alleged to have fallen off a bookcase. The sculpture presumably fell a distance of 1.43 m and the corner that struck him had an area of 0.25 cm2. If the time for the sculpture to stop was 1.00 ms, the pressure on his temple, in N/m2, was...

2. i know pressure is : p=F/A
A(area)= 2.5*10^(-5)m^2
and the answer is p=8.88*10^(8)N/m^2

but i cant get force in any way
i know its F=ma, but whatever i try doesnt work. please help.

Last edited by a moderator: May 5, 2014
2. May 5, 2014

### paisiello2

Do you know what an impulse is?

3. May 5, 2014

### ron360

in know its change in momentum which is mv, but how would you apply to my force?

4. May 5, 2014

### paisiello2

A force is also a change in momentum, right?

5. May 5, 2014

### ron360

yeah but change i get is F=6.006*10^8(kg*m/s^2) and its not the actual force

6. May 5, 2014

### Staff: Mentor

Change in momentum and force have some relationship you can use (together with one of the values from the problem statement).

7. May 5, 2014

### paisiello2

Maybe show all your work explicitly so we can find out where you are going wrong.