We know that whatever amount we start with, half of it decays and forms atoms of other elements in 175 hours. So in order to figure out how much is left after 525 hours, we'll need to know how many half-lifes pass in that amount of time.
Well, (525 divided by 175) is exactly 3 half-lifes. So this will be easy.
-- After 1 half-life . . .
. . . . . 50% decays, 50% is still there.
-- After the 2nd half-life . . .
. . . . . (half of the leftover 50%) = another 25% decays, 25% is left.
-- After the 3rd half-life . . .
. . . . . (half of the leftover 25%) = another 12.5% decays, 12.5% is left.
12.5% of 4,000g = (0.125 x 4,000g) = <em>500 g</em> .
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<u>Another way</u>:
After 1 half-life, 1/2 is left.
After 2 half-lifes, 1/4 is left.
After 3 half-lifes, 1/8 is left.
1/8 of 4,000g = (4,000g/8) = <em>500 g </em>.
A non-example of force would be something that stay sill like a balloon in the air..... taste, smell, feel, texture, color, opinion, faith, hope, sincerity, honest, speed, momentum, altitude, volume, loudness, area, length, acidity, obesity, nationalism, current, resistance, viscosity, wavelength, flow, rate, frequency, albedo, diameter, age, temperature, acceleration, body mass index, salinity, specific, specific gravity, consciousness, intelligence, refraction index, mass, time, date rate, switching speed, libido, focal length, and latency are not force. And even there are many other things that also are not force, too.
