Given, the expression of potential energy,
u=(2−20x+5x2) J
Applying the expression of relation between force and potential energy, we have,
F=−dudx
=−ddx(2−20x+5x2)
=−(0−20+10x)
⇒F=−10x+20
At equilibrium position (mean position),
F=0
⇒−10x+20=0
⇒x=2 m
Hence, mean position is at
x=2 m
Thus, amplitude of motion,
A=|−3|+2=5 m
Therefore, after reaching
x=2 m, particle will move further by
5 m i.e. till
x=2+5=7 m.
Hence, maximum value of
x is
7 m.
Accepted answer: 7, 7.0, 7.00