Aball is traveling at 60m/s, then increases to 90m/s in 3 second, what is the average velocity?

75 m /s

Explanation:

Acceleration of ball a = change in velocity / time

=( 90 - 60)/ 3 = 10 m s⁻²

Initial velocity u = 60 m/s

a = 10 m s⁻²

time t = 3

distance traveled s = ut + 1/2 at²

= 60 x 3 + .5 x 10 x 3 x 3

= 225 m

Average velocity = total distance traveled /time

= 225 / 3 = 75 m/s

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..

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.