Acrate is lifted vertically 1.5 m and then held at rest. the crate has weight 100 n (i. e., it is reese (enr647) – hs onramps 04: intro to work and energy – mcdaniel – (34472020) 2 supported by an upward force of 100 n). how much work is being done to hold the crate 1.5 m above the ground in this way?

150Joules

Explanation:

Work is said to be done if a force is applied to cause a body to move through a distance.

Work done = Force × distance

Given force = 100N

Distance = 1.5m

Work done = 100 × 1.5

Work done = 150Joules.

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.