6. Within 4.0 s of liftoff, a spacecraft that is uniformly accelerating straight upward from rest reaches an altitude
of 4.50 X 10m (up).
(a) What is the spacecraft's acceleration?
(b) At what velocity is the spacecraft travelling when it
reaches this attitude

What happens when chlorine reacts with bromine? a. electrons move from the chlorine atoms to the bromine atoms. b. electrons move from the bromine atoms to the chlorine atoms. c. electrons are shared between the chlorine atoms and the bromine atoms. d. electrons become delocalized among the atoms.

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.

What object a collides with object b and bounces back its final momentum is?