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:
dont have the answer but you cute
Explanation:
Answer:
It requires more tension to pull up the track
Explanation:
Net force must be zero to maintain constant velocity.
Weight force will always be pointed down the slope. Call it W
Friction force (Call it Ff) will be down slope when movement is up slope.
Friction force will be up slope when movement is down slope.
W and Ff are always positive numbers
Call the pulling force T
If Up slope is considered the positive direction
Moving up slope
Tu - Ff - W = 0
Tu = Ff + W
Moving down slope
Td + W - Ff = 0
Td = Ff - W
Ff + W > Ff - W therefore Tu > Td
Answer:
p = mv
Explanation:
The momentum of an object is given by the equation:
where
m is the mass of the object
v is the velocity
Since velocity is a vector, it follows that momentum is a vector as well, therefore it has a magnitude and a direction (the same as the velocity).
The SI unit of the momentum is
An important law related to the momentum is the law of conservation of momentum, which states that for an isolated system (= zero net external force on it), the total momentum of the system is conserved.