Timeline for Translational motion of a rigid body
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 22, 2017 at 20:04 | comment | added | Johnathan Gross | The back wheels are slipping so the bottom is moving backwards. Friction opposes the backwards motion, by pushing forwards. | |
| Jul 22, 2017 at 20:03 | comment | added | Eman.suradi | If the back wheels are slipping, then friction acts to oppose this slipping, i.e it will act in the opposite direction of motion . How could the car accelerate ? | |
| Jul 22, 2017 at 19:57 | vote | accept | Eman.suradi | ||
| Jul 22, 2017 at 19:53 | comment | added | Johnathan Gross | Yes. Rolling means that the point of contact does not slip. | |
| Jul 22, 2017 at 19:50 | comment | added | Eman.suradi | And since the back wheels are slipping , kinetic friction is acting on the back wheels ? | |
| Jul 22, 2017 at 19:49 | comment | added | Eman.suradi | The back wheels are slipping means they are only sliding like a box sliding on a surface . They are not rolling with slipping , true ? | |
| Jul 22, 2017 at 19:33 | comment | added | Johnathan Gross | No. Since the back wheels are slipping, only static friction can act. The front wheels aren't being powered by the engine, so they aren't being forced to move. Because they aren't being forced to move, they can stay in contact with the ground without slipping. No slipping means static friction, which can be any value between 0 and $\mu_sN$. Keeping the wheel rolling instead of slipping doesn't require as much force as pushing the whole car. | |
| Jul 22, 2017 at 18:14 | comment | added | Eman.suradi | I want to check that I understand your answer . Since the back wheels are slipping very fast , this means the distance travelled by the wheels will be less , so the angular acceleration of the front wheels will be small (since the distance travelled is small) , and thus the friction produced by the front wheels is small , true ? | |
| Jul 22, 2017 at 18:02 | comment | added | Johnathan Gross | Rotational kinetic energy also exists. When an object spins, it has kinetic energy. When an object moves from one location to another, it has kinetic energy. The wheels spinning hold kinetic energy in addition to the translational kinetic energy of the car moving. If the wheels are massless, they have no moment of inertia, and therefore can' t have rotational kinetic energy. | |
| Jul 22, 2017 at 17:55 | comment | added | Eman.suradi | "Neglecting the wheels means that all the force from friction does work towards the car's translational motion." I didn't understand this sentence Sir | |
| Jul 22, 2017 at 16:23 | history | answered | Johnathan Gross | CC BY-SA 3.0 |