Un bobsleigh est lancé le long d'une piste glacée et étroite, en ligne droite, où les frottements sont négligeables. 1. Faire un bilan des interactions qui s'exercent sur le bobsleigh.
2. Faire un schéma représentant les forces qui s'exercent sur le bobsleigh.
Que peut-on dire de ces forces ?
3. En déduire la nature du mouvement du bobsleigh.​

22. the effect of threshold braking is to a cause skids. b. lock wheels. c. prevent locking of wheels. d. increase stopping distance.

Mutt and jeff are running along a path each pushing a cart loaded with rocks. if mutt's wagon has a mass two times greater than jeff's and they want to stay together, arriving at their destination at the same time, what must happen? a) jeff should slow down so mutt can catch up. b) mutt must use half as much force to push his cart. c) mutt must use twice as much force to push his cart. d) mutt and jeff will use the same force, but mutt will take bigger steps.

Which component of the earth’s atmosphere is decreased due to photosynthesis?