Determine the lattice vectors a, b and c of the primitive unit cell for the face-centred cubic lattice in terms of cartesian unit vectors i, j and k. assume the cube has side length a. (b) prove that the cell bounded by your vectors is a primitive cell. (c) assume that there is a single spherical atom at each lattice point of the foc lattice, and that these atoms pack the volume as densely as possible (close-packed). determine the fraction of volume that is occupied by "atoms” in this structure. (note, this is called the packing fraction.)

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

the answer you are looking for is d. there are no holes for blood to enter or leave the system. your welcome