Atest rocket is launched vertically from guard level (y= 0m) at time t = 0.0s. the rocket engine provides constant acceleration during the burn phase. at the instant of the engine burnout the rocket has risen to 49m and acquired a velocity of 30 m/s. how long did the burn phase last

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e