A plane monochromatic electromagnetic wave with wavelength λ=2.0cm, propagates through a vacuum. Its magnetic field is described by >B⃗ =(Bxi^+Byj^)cos(kz+ωt), where Bx=1.9×10−6T, By=4.7×10−6T, and i^ and j^ are the unit vectors in the +x and +y directions, respectively. What is Sz, the z-component of the Poynting vector at (x=0,y=0,z=0) at t=0?

root word, prefixes, and suffixes

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 old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form