70.5
13. determine the frequency of a microwave 6.0 cm in length. (a microwave is an
electromagnetic wave. it travels through space at a speed of 3.0 x 10^8 m/s)

5000000000hertz

Explanation:

Wavelength=6cm=6/100 m=0.06m

Frequency=velocity/wavelength

Frequency=(3×10^8)÷0.06

Frequency=5000000000 hertz

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.