ALWAYS use significant figure rules. Remember that these rules apply to all numbers that are measurements. A 4,000-kg car traveling at 20 m/s hits a wall with a force of 80,000 N and comes to a stop. What was the impact time?

Ahypothetical metal has an orthorhombic unit cell for which the a, b, and c lattice parameters are 0.413 nm, 0.665 nm, and 0.876 nm, respectively. (a) if there are 8 atoms per unit cell and the atomic packing factor is 0.536, determine the atomic radius (in nm). (b) if the density is 3.99 g/cm3, calculate the metal's atomic weight (in g/mol).