Answer:
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
Equation for Half life :
A = a(0.5)^(t/h)
A is current amount, "a" is initial amount, h is halflife, t is time
5 = 40(0.5)^(t/1.3x10^9)
5/40 = (0.5)^(t/1.3x10^9)
take the log of both sides , power rule
Log(5/40) = (t/1.3x10^9) * Log(0.5)
(1.3x10^9) * Log(5/40) / Log(0.5) = t
3.9x10^9 years = t
And if you think about what a half life is, the time it take for the amount to reduce to half.
40/2 = 20
20/2 = 10
10/2 = 5
It went through 3 half-lifes
3 * 1.3x10^9 = 3.9x10^9 years
Answer:
20.1169 Km/hr
Explanation:
<em>10 laps around a 1320-foot track in 12 minutes.</em>
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Total distance = 10 * 1320 foot = 13200 foot
Time = 12 minutes
Converting to Kilometers and hour;
1 Foot is equal to 0.0003048 Kilometers;
13200 foot = x kilometer
Total distance = 4.02336 kilometer
Time = 12 / 60 = 0.2 hour
Speed = Distance / Time = 4.02336 / 0.2 = 20.1169 Km/hr