Answer:
its c
Explanation:i am big brain give me brainilest
Answer:
F = M a is the vector equation involved
F = T - M g are the forces acting on the elevator (scalar equation)
T - M g = M a
T = M (a + g) remember this a scalar
If a is slowing down then it must have a positive acceleration upwards
Therefor the tension in the cable must be greater than zero
When the tension increases to M g, a has increased to zero
For a to be zero, no acceleration, T = M g
Yes, if the mass starts at rest, <u>the change in speed will be equal the final speed</u>, because:
Δv = Vf - Vo
How Vo (Initial velocity) is equal zero, we simplificate:
Δv = Vf
Then, the change of the speed, if the mass starts at rest, will be equal to final velocity.
Greetings.
Answer:
A half-life is the time required for one half of the nuclei in a radio- active isotope to decay.
Explanation:
A radio-active isotope is an isotope which undergoes radioactive decay.
Radioactive decay is a spontaneous process in which the nucleus of an atom changes its state (turning into a different nucleus, or de-exciting), emitting radiation, which can be of three different types: alpha, beta or gamma.
The half-life of a radio-active isotope is the time required for half of the nuclei of the initial sample to decay.
The law of radio-active decay can be expressed as follows:
where
N(t) is the number of undecayed nuclei left at time t
N0 is the initial number of nuclei
t is the time
is the half-life
We see that when 
(that means, when 1 half-life has passed), the number of undecayed nuclei left is
So, half of the initial nuclei.
Rutherford overturned Thomson's model in 1911 with his well-known gold foil experiment in which he demonstrated that the atom has a tiny and heavy nucleus. Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure.
