During a test crash, a 1,450kg sedan accelerates from rest at a constant acceleration of 5m/s^2 for 20m until it collides with a concrete wall. What
is the change in kinetic energy when the car strikes the wall and comes to
a stop?

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value

Two 2.0-cm-diameter disks face each other, 1.0 mm apart. they are charged to ±10 nc. what is the electric field strength between the disks? a proton is shot from the negative disk toward the positive disk. what launch speed must the proton have to just barely reach the positive disk?

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.