One of the statements below is correct In an ideal system where all forms of friction are ignored?
a. Gravitational potential energy is transformed into Kinetic energy and vice versa
b. Gravitational energy is transformed to thermal energy
c. Kinetic energy is not transformed to gravitational potential energy
d. All of the above

a.

Explanation:

In a perfect system then energy can be changed from Kinetic to Gravitational Potential and vice versa without any losses. A common form of loss would be thermal energy, so b. is not the answer. c. is invalid as we want these 2 forms of energy to be transferred between, and d. is invalid as these statements c and a contradict each other.

c. 7/3

step-by-step explanation:

a rational number is like pi- it is a repeating decimal.

a. is -1.8

b. 2.236068

c. 2.3333333333333333333

d.   is 3

i hope that ! =)

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.