Average magnitude of force during a 0.4 second impact

[Crushgear64]

Homework Statement

A 40kg branch falls 5.5m and lands on a roof. The roof withstood the the impact.

Homework Equations

If the impact time was 0.4 second calculate the magnitude of the average force exerted on the roof during the impact.

The Attempt at a Solution

F=ma doesn't seem right because it's in free fall though.
P=mv ≈ 415
415/0.4=1037.5N?

Is this right?

 

[SammyS]

Homework Statement

A 40kg branch falls 5.5m and lands on a roof. The roof withstood the the impact.

Homework Equations

If the impact time was 0.4 second calculate the magnitude of the average force exerted on the roof during the impact.

The Attempt at a Solution

F=ma doesn't seem right because it's in free fall though.
P=mv ≈ 415
415/0.4=1037.5N?

Is this right?

That is correct !