100 POINTS!! PLEASE DONT ANSWER UNLESS YOU KNOW BOTH ANSWERS PLEASE. If a bike hits a rock and suddenly stops, the rider flies over the handlebars due to .
A. absolute zero B. displacement C. inertia D. electromagnetic spectrum

During a track meet, Sarah ran 400m in 80s. What was her average speed? (Remember s=d/t)

A. 5 m/s

B. 20 m/s

C. 15 m/s

D. 15 mph

1. is B and 2. is A

Explanation:

1. Displacement

2.  5 m/s  400 ÷ 80 = 5

Explanation:

answer; /// the above statement is (true);

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.