1. a 1-in diameter solid round bar has a groove 0.1in deep with a 0.1-in radius machined into it. the bar is made of aisi 1040 cd steel and is subjected to a purely reversing torque of 1950 lbf·in. for the s-n curve of this material, let f = 0.85. (a) estimate the number of cycles to failure (b) if the bar is also placed in an environment with a temperature of 750°f, estimate the number of cycles to failure.

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.

graph question answered .. you think better when you are relaxed and happy

laticia draws the diagram below to show earth’s magnetic field.

answer

the arrows to the right of earth should point up.

its c i just checked it