Q. What should be the spring constant of a spring designed to bring a 1400 car to rest from a speed of 95 so that the occupants undergo a maximum acceleration of 5.0?
Q. A parallel-plate air capacitor is made from two plates 0.070 m square, spaced 3.5 mm apart. What must the potential difference between the plates be to produce an energy density of 0.067 J/m^3?