Answer:
3
Explanation:
The half-life of a radioactive isotope is the time it takes for the mass of the sample to halve.
This can be rewritten as follows:
where
m(t) is the mass of the sample at time t
m0 is the original mass of the sample
n is the number of half-lives that passed
We see that if we take n=3, the amount of original sample left is
So 3 (3 half-lives) is the correct answer.
Answer: 75,242.9 m/s
Explanation:
from the question we are given the following parameters
mass of Lion (ML) = 169,169 kg
velocity of lion (VL) = 777,377.7 m/s
mass of Gazelle (Mg) = 31,731.7 kg
velocity of Gazelle (Vg) = 63,863.8 kg
mass of Lion and Gazelle (M) = 200,900.7 kg
velocity of Lion and Gazelle (V) = ?
The first figure below shows the motion of the Lion and Gazelle with their direction.
The second diagram shows the motion of the Lion and Gazelle with their directions rearranged to form a right angle triangle.
from the triangle formed we can get the velocity of the Lion and Gazelle immediately after collision using their momentum and Phytaghoras theorem
momentum = mass x velocity
momentum of the Lion = 169,169 x 77,377.3 = 13,089,840,463.7 kgm/s
momentum of the Gazelle = 31,731.7 x 63,863.8 = 2,026,506,942.46 kgm/s
momentum of the Lion and Gazelle = 200,900.7 x V
now applying Phytaghoras theorem we have
13,089,840,463.7 + 2,026,506,942.46 = 200,900.7 x V
15,116,347,406.16 = 200,900.7 x V
V = 75,242.9 m/s
Answer:
The latent heat of fusion of water is 334.88 Joules per gram of water.
Explanation:
Let the latent heat of ice be 'x' J/g
1) Thus heat absorbed by 100 gram of ice to get converted into water equals
2) heat energy required to raise the temperature of water from 0 to 25 degree Celsius equals
Thus total energy needed equals
3) Heat energy released by the decrease in the temperature of water from 25 to 11 degree Celsius is
Now by conservation of energy we have