Calculate the work required to move a planet’s satellite of mass 1820 kg from a circular orbit of radius 2r to one of radius 3r, where 7.37×106 m is the radius of the planet. the mass of the planet is 7.51 × 1024 kg. answer in units of j.

The work required to move a planet's satellite is W = 2854.61 J

Explanation:

Given data,

The mass of the satellite, m = 1820 kg

The radius of the circular orbit, r =  2R

The radius of the planet, r = 5.37 x 10⁶ m

The mass of the planet, M = 7.5 x 10²⁴ kg

The formula for work done from the 2R to 3R is,

                            W =

                            W = GMm/3R - GMm/2R

                             W = (-0.17)GMm/R  J

The negative sign indicates that the energy stored in the satellite as the potential energy.

Substituting the values

                              W = (-0.17) 6.673 x 10⁻¹¹ X 7.51 x 10²⁴ X 1820 / (7.37 x 10⁶)²

                                  = -2854.61 J

Hence, the work required to move a planet's satellite is W = 2854.61 J

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.

powerful computers now, not then