- #1
TjGrinnell
- 11
- 1
- Homework Statement
- A door has a mass of 9.00 kg, a height of 2.00 m, a width of 1.00 m, and a moment of inertia of 3.00 kg*m2 about its axis. It is initially at rest and partly open. A 2.00 kg ball is thrown at the door. When it hits the door it is 1.20 m above the floor and 0.450 m from the hinge axis. It is moving at 3.50 m/s perpendicular to the door's surface, and it bounces back, also perpendicular to the door's surface at 2.00 m/s.
What is the angular speed of the door after the collision
If the collision takes place over 0.05 s, what was the average force between the ball and the door?
- Relevant Equations
- KE[SUB]b1[/SUB]+PE[SUB]d[/SUB]=KE[SUB]b2[/SUB]+KE[SUB]d[/SUB]
F[SUB]avg[/SUB]=m(v[SUB]f[/SUB]-v[SUB]0[/SUB])/t
Have to type here because of picture. I think I may have done this wrong the first time and I wanted to know if i should use the conservation equation as shown above, or I the one in my work correct?
And also is the second formula the correct one in order to get the average force?
Thank you