In a car moving at constant acceleration, you travel 290 m between the instants at which the speedometer reads 40 km/h and 80 km/h . part a part complete how many seconds does it take you to travel the 290 m ?

 Car will take 17.36 seconds to travel the 290 meter.

Explanation:

   We know the equation of motion , where s is the displacement, u is the initial velocity, a is the acceleration and v is the final velocity.

  In this case initial velocity = 40 km/h = 11.11 m/s

                      Final velocity = 80 km/h = 22.22 m/s

                      Displacement = 290 m

   Substituting         

 Now we have v = u+at, where t is the time taken.

   Substituting

            22.22 =11.11 + 0.64*t

                     t = 17.36 seconds

So car will take 17.36 seconds to travel the 290 meter.

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.