We have that the speed of the object between 60 to 70 seconds

From the question we are told
The speed of the object between 60 to 70 seconds
Generally the equation for Average speed is mathematically given as

Where

Therefore

In conclusion
The speed of the object between 60 to 70 seconds

For more information on this visit
brainly.com/question/23379286?referrer=searchResults
Adding neutron to the nucleus creates new isotopes of that element. Mass of the nucleus will increase if you add neutron to it but element will remain the same. If you add proton to the nucleus, mass of the nucleus will change but also element will also change. That is, atom of the element will change.