A bungie jumper of mass 50kg is attached to a bungie with a constant of 100Nm. The unstretched length of the bungie is 15m. What is the maxmimum velocity of the jumper

v = 18.5 m /s

Explanation:

The velocity of the jumper will go on increasing until his weight is more than the restoring force created in the bungle.

mg = kx

50 x 9.8 = 100 X

X = 4.9 m

Total fall = 15 + 4.9 = 19.9 m

kinetic energy gained due to fall by 19.9 m

= mgh = 50 x 9.8 x 19.9 = 9751 J

energy lost due to stored elastic energy in bungie

= 1/2 k x²

= .5 x 100 x 4.9²

= 1200.5 J

Remaining kinetic energy = 9751 - 1200.5 = 8550.5 J

1/2 m v² = 8550.5

.5 x 50 x v² = 8550.5

v² = 342

v = 18.5 m /s

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper.

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.