For a top player, a tennis ball may leave the racket on the serve with a speed of 55 m/s (about 120 mi/h). if the ball has a mass of 0.060 kg and is in contact with the racket for about 4 ms (4 x 10-3 s), estimate the average force on the ball. would this force be large enough to lift a 60-kg person?

Yes is large enough

Explanation:

We need to apply the second Newton's Law to find the solution.

We know that,

And we know as well that

Replacing the aceleration value in the equation force we have,

Substituting our values we have,

The weight of the person is then,

We can conclude that force on the ball is large to lift the ball

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.