Aboeing 747 "jumbo jet" has a length of 59.7 m. the runway on which the plane lands intersects another runway. the width of the intersection is 25.0 m. the plane decelerates through the intersection at a rate of 5.4 m/s2 and clears it with a final speed of 53 m/s. how much time is needed for the plane to clear the intersection?

t = 1.48 s

Explanation:

As we know that length of the Boeing plane is

width of the intersection is given as

now we know that deceleration of the plane is given as

Also the final speed of the plane while it clears the intersection is given as

now we have

also we know that

now we have

by solving above equation we have

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.

positive reinforcement? ?