Nowadays, most of the walkie talkies ... and all R/C models ... operate in the "Family Radio Service" (FRS) band. That's 46-49 MHz. The wavelength is 6.12-6.52 meters.
17. C. Isotopes
18. Tracers
19. Alpha Decay
the velocity at which the boy see the ball go by is 7ms-1
The attraction between two objects is force.
As such, if you don't describe the degree of attraction
in units of force, you're doomed.
Whether to use micronewtons, millinewtons, newtons,
giganewtons, ounces, pounds, or tons, really depends on
the size of the force, which in turn depends on the masses
of the two objects and the distance between them. You'll
want to select the unit that produces the most convenient
number. And of course, you'll want to favor the SI units.
