<span>3.2 grams
The first thing to do is calculate how many half lives have expired. So take the time of 72 seconds and divide by the length of a half life which is 38 seconds. So
72 / 38 = 1.894736842
So we're over 1 half life, but not quite 2 half lives. So you'll have something less than 12/2 = 6 grams, but more than 12/4 = 3 grams.
The exact answer is done by dividing 12 by 2 raised to the power of 1.8947. So let's calculate 2^1.8947 power
= 12 g / (e ^ ln(2)*1.8947)
= 12 g / (e ^ 0.693147181 * 1.8947)
= 12 g / (e ^ 1.313305964)
= 12 g / 3.718446464
= 3.227154167 g
So rounded to 2 significant figures gives 3.2 grams.</span>
Answer: same
Explanation: They both weigh a kilogram and there is no friction
Answer:
Explanation: find the attached solution below
Answer:
Coefficient of friction = 0.836
Explanation:
If v be the speed after one quarter of the circular path
v² = 2as = 2 x 1.85 x 2πr/4 ; v²/r = 1.85 x 3.14 = 5.8
tangential acceleration = 5.8 m/s²
radial acceleration = v² /r = 5.8
total acceleration = √2 x 5.8
m x√2 x 5.8 = m x g xμ
μ = √2 x 5.8 / 9.8 = 0.836
