A graph labeled velocity versus time with horizontal axis time (seconds) and vertical axis velocity (meters per second). A blue line runs straight across at 2 units on the vertical axis for all horizontal axis values. Based on the graph of velocity over time, which could be the initial velocity and the final velocity for this graph?

initial = 0 m/s; final = 2.5 m/s
initial = 2.5 m/s; final = 2.5 m/s
initial = 3.0 m/s; final = 6.0 m/s
initial = 6.0m/s; final = 3.0 m/s

B

Explanation:

It's because the line keeps going straight meaning it has a constant velocity from beginning to end.

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

photocells convert light energy to electricity