i think this is another momentum question

[rottentreats64]

i really have no clue what to do in this problem since theres a measurement for the dent...what formula am i supposed to use for this????


4. During an autumn storm, a 0.012kg hail stone traveling at 20.0m/s made a 0.20 cm deep dent in the hood of Darnell’s new car. What average force did the car exert to stop the damaging hail stone?
so far i understand:
mass= .012kg
velocity= 20 m/s
and then theres the .20 cm deep dent but i dun knoe whats that need for?

[turdferguson]

You could probably use momentum or kinematics, but the work-energy theorem is a better place to start

[Hurkyl]

Can you describe, in detail, the trajectory that the hailstone has travelled, and everything that's happened to it?

[ponjavic]

Would it be right to use v^2=-2*a*s to find the acceleration and then force

If you do not know v^2=u^2+2as try to derive it using:

v=u+at

s=ut+at^2/2

[turdferguson]

Would it be right to use v^2=-2*a*s to find the acceleration and then force

If you do not know v^2=u^2+2as try to derive it using:

v=u+at

s=ut+at^2/2

But its a lot easier with energy. W=-KE0
Fd=KEo
F=KEo/d=mv^2/2d
Everything you need to plug in is given, using acceleration is reproving the work energy theorem with kinematics.

[lotrgreengrapes7926]

We had a similar problem in our physics class, but my physics teacher says the solution is incorrect.
1) How long was the impact, if it traveled .2 cm at 20 m/s? (This is the part that is incorrect.)
2) Ft=m(v_2-v_1)