Answer:
Mass number - ⦁ The number of protons and neutrons in the nucleus of an atom.
Isotopes - ⦁ Atoms with the same number of protons, but different number of neutrons.
Nitrogen - ⦁ The name of the element with atomic number 7.
Atomic number - ⦁ The number of protons in the nucleus of an atom.
Answer:

Explanation:
Given two mass on an incline code
and
and an angle of inclination
.
. Assume that
is the weight being pulled up and
the hanging weight.
-The equations of motion from Newton's Second Law are:
where a is the acceleration.
#Substituting for
(tension) gives:

#and solving for 
which is the system's acceleration.
Answer:
Part a)

Part b)
North of East
Explanation:
Speed of train towards East = 60 km/h
displacement towards East is given as

now it turns towards 50 degree East of North
so its distance is given as


then finally it moves towards west for 50 min

Now the total displacement of the train is given as



now total time duration of the motion is given as


now average velocity is given as


Part a)
magnitude of the average velocity is given as



Part b)
Direction of the velocity is given as


North of East