A train has a velocity of 44 metre per second and an acceleration of 4 metre per second square. its velocity after 10 seconds is what

Acceleration=Final velocity-Initial velocity /time.

Acceleration=a=4m/s².

Initial velocity= u= 44m/s

Final velocity=v= let it be v, since we are to look for the final velocity.

Time=t=10seconds.

Mathematically:

a=v-u/t

Substituting the givens into the equation.

4=v-44/10

cross multiply.

4×10 = v-44

40=v-44

40+44=v

v=84m/s

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.

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray