A59 g arrow is shot straight up into the air with a speed of 25 m/s. it reaches a maximum height of 30.8878 m. find the initial kinetic energy. the acceleration of gravity is 9.8 m/s 2 . answer in units of j.

18.44 J

Explanation:

Kinetic energy is the energy possessed by objects due to the fact that they are moving. It is half the product of the objects mass and the square of its velocity

K.E = 0.5mv²

     = 0.5 * 0.059 kg * (25 m/s)²

     = 18.44 J

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.

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27