Timeline for Does applying momentary torque cause a square object to take off?
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 5, 2020 at 15:24 | comment | added | R.W. Bird | It has kinetic energy, both linear and rotational, as a result of the impulse from the bullet. | |
| May 5, 2020 at 14:24 | comment | added | sslucifer | What do you mean by it pushes the ground? The cube is a rigid body it can't be compressed so it will not store any energy that will later be used to lift itself from the ground. | |
| May 5, 2020 at 14:21 | comment | added | R.W. Bird | As the block tries to rotate, it pushes down on the lower right corner. The surface responds by pushing back. This is the force that lifts the center of mass, and may give it enough vertical velocity for the block to lose contact with the surface. | |
| May 5, 2020 at 13:53 | comment | added | sslucifer | I don't that's possible just from the horizontal force of bullet. To fly off, the cube needs some external vertical force to overcome gravity. It may be possible when you shoot the bullet at some angle, so that there will be a component of force in the vertical direction, but in the case stated not possible. | |
| May 5, 2020 at 5:34 | comment | added | George Menoutis | Pardon me for not being clear.The question is not whether the cube will rotate at least 90 degrees - it is whether it will "fly" (stop touching the ground with any points) | |
| May 4, 2020 at 21:24 | comment | added | sslucifer | OP has mentioned that the collision is 100% elastic. Since the block is not moving then the friction is not acting at the instant of collision. I know this is quite subtle approach but I can't think of another analysis. | |
| May 4, 2020 at 21:22 | comment | added | R.W. Bird | A bullet fired into a block does not conserve energy. With friction at the lower surface it also does not conserve linear or angular momentum. | |
| May 4, 2020 at 18:37 | history | answered | sslucifer | CC BY-SA 4.0 |