A force of 18 lb is required to hold a spring stretched 4 in. beyond its natural length. How much work W is done in stretching it from its natural length to 6 in. beyond its natural length

W = 36 lb-in

Explanation:

Given:

Force required to pull a spring (F) = 18 lb

Elongation in the spring (x₁) = 4 in

New elongation (x₂) = 6 in

We know that, the force required to stretch or compress the spring is given by the formula:

Express in terms of 'k'. This gives,

Now, plug in 'F' and 'x₁' values and solve for 'k'. This gives,

Now, work done in stretching or compressing a spring by a length of 'x' is given as:

Here, . Solve for work, 'W'. This gives,

Therefore, the work done in stretching it from its natural length to 6 inch beyond its natural length is 36 lb-in

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.

a, c, d, e are all applying about success strategies.