Question 1. A satellite’s velocity is 30,000m/s. After 60 seconds, it’s velocity slows to 15,000 m/s. What is the satellite’s acceleration?

Question 2. A speed boat increases its speed from 42 m/s to 88m/s in a 4 second period. What is the acceleration during this period?

Explanation:

1.

Initial speed of satellite is 30,000 m/s

Final speed of satellite is 15000 m/s

Time taken by the satellite to reach final speed is 60 s

The satellite’s acceleration is equal to the change in velocity divided by time taken. So,

2.

Initial speed of a boat is 42 m/s

Final speed of a boat is 88 m/s

Time taken is 4 s

The acceleration of boat during this period is :

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.

choosing tennis and golf balls is your inde choice.

their mass and volume are dep