Answer:
10 days
Explanation:
The half-life of a radioactive sample is the time taken for half of the sample to decay.
In the diagram, the half-life corresponds to the time after which the % of cobalt-57 has halved. We can observe the following:
At t=10 days, the % of Co remaining is approximately 45%
At t=20 days, the % of Co remaining is approximately 22%
This means that the sample of cobalt-57 has halved in 10 days, so the half-life of cobalt-57 is 10 days.
Answer:
False
Explanation:
The net force is equal to the applied force minus the force of friction. It is possible for friction to act in the same direction as an applied force, but that would mean there would have to be more than two forces acting on the object.
Answer:
Explanation:
From the question we are told that:
Mass of astronaut 
Mass of tool 
Distance 
Velocity of separation 
Velocity of tool bag 
Generally the equation for momentum is mathematically given by
Therefore
Initial Momentum before drop
Initial Momentum after drop
Therefore
Since 
Generally the equation for Time T is mathematically given by
Answer:
4500 million years
Explanation:
The Sun shines thanks to the thermonuclear conversion of hydrogen to helium inside. It is currently 4,500 million years old and has reservations for a similar period of time. When this fuel is exhausted in the central region, the heart of the Sun, constituted of helium and in an inert state, will contract and put more external fuel reserves within reach of the star, with which this mass of helium will grow over time . When that happens, the Sun will evolve into a giant star that will reach the orbit of Mars and, therefore, destroy the planet Earth.
As the helium heart mass increases so do the central density and temperature. When it reaches 100 million degrees, helium fuses thermonuclearly with itself and becomes a mixture of carbon and oxygen.
When the helium runs out in the center, the previous operation is reproduced approximately. The carbon / oxygen heart contracts and the helium and hydrogen of the surrounding layers are placed within the reach of thermonuclear combustion. The difference is that this double combustion is unstable and the density is so high that electrons can, alone, stabilize the heart of carbon and oxygen. The end result is that the outer layers, which originate a planetary nebula, are expelled, and the old thermonuclear reactor becomes visible, which becomes a white dwarf that slowly cools like the embers of a fire over billions of millions. of years.
