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derive second law of motion S=ut+1/2at^.... please ❤
Answers
Answer:
Derive second law of motion:
Explanation:
So far we have the equations: v = u + at and s = ½ (u+v) t
The second can be useful for finding displacement. However, if we don't know the final velocity, it's useless.
We could first work out v from "v = u + at". But let's be radical and substitute "v = u + at" into the second equation!
s = ½ (u + v) × t
s = ½ (u + u + at) × t
s = ut + ½ at²
A third equation, useful for finding displacement when you know the initial velocity, time and acceleration.
#BAL
☘ Correct Question:-
⛄ Derive the second equation of motion.
☘ Derivation of the Second equation of Motion --Position-time relation [ Graphical method] :-
⛄ s = ut + 1/2 at²
_______________________________________
⛄ Here,
OA = u = initial velocity.
OE = v = final velocity.
OC = t = time taken.
Now,
S = Area under graph AB.
=> s = Area under trapezium OABC.
or
s= Area of ∆ABD + area of the rectangle OADC.
=> s = 1/2 × b × h + l × b.
Now,
On substituting the values from the graph, we get,
s = 1/2 × AD × BD + OC × OA
=> s= 1/2 × AD × (BC - DC) + OC × OA
=> s = 1/2 × t × (v - u) + t × u
=> s = 1/2 × (v- u) t + ut .......→ (i)
From 1st equation of the motion, we know that,
v = u + at
=> at = v - u .....→ (ii)
Now,
On substituting the equation (ii) in equation (i), we get,
s = 1/2 × (v-u)t + ut
=> s = 1/2 × (at)t + ut
=> s = 1/2 × at² + ut
Now, on reordering the terms, we get,
☞ s = ut + 1/2 at²
[2nd Equation of motion]