Earth is subject not only to the gravitational force of the moon but also to the gravitational pull of the sun. however, earth is much farther away from the sun than it is from the moon. in fact, the center of earth is at an average distance of 1.5×1011m from the center of the sun. given that the mass of the sun is 1.99×1030kg, which of the following statements is correct?

a. the force exerted on earth by the sun is weaker than the corresponding force exerted by the moon.
b. the force exerted on earth by the sun is stronger than the corresponding force exerted by the moon.
c. the force exerted on earth by the sun is of the same order of magnitude of the corresponding force exerted by the moon.

option (B)

Explanation:

The gravitational force on earth depends on the mass of sun and the distance of sun from earth.

As the mass of sun is much more than the mass of moon, so the gravitational force of sun on earth is much more than the force on earth due to the moon.

The distance does not matter because the mass of sun is much more.

what best describes physical development during adolescence is the development of secondary sex characteristics happens at a rate unique to each individual.

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.