The figure shows the potential energy of a 400g particle as it moves along the x-axis. suppose the particle's mechanical energy is 12 j.
where are the particle's turning points?
what is the particle's speed when it is at x= 2.0m?
what is the particle's maximum speed?
at what position or positions does this occur?

the particle's turning points :  x = 1, x = 2, x = 4.

the particle's speed when it is at x= 2.0 : v = 4,472 m/s

the particle's maximum speed : v = 7,746 m/s, at x=1 and x=4

Energy is the ability to do work

Energy because its motion is expressed as Kinetic energy (KE) which can be formulated as:

So for two objects that have the same speed, the greater the mass of the object, the greater the kinetic energy

Whereas for a stationary object it has kinetic energy = 0

While the energy produced from its position is called potential energy (PE)

which can be formulated as:

 Ep = m. g. h ⇒ gravitational potential energy

The sum of kinetic and potential energy is called mechanical energy

The particle's turning points is the point where the particle changes its direction of motion, because the motion of a particle can be considered as a vector

In the picture, turning points are shown at x = 1, x = 2, x = 4.

The potential energy (PE) value in the figure when x = 2 is 8 J

Because it is known that ME = 12 J, particle velocity can be found from the kinetic energy equation

KE = ME - PE

KE = 12 - 8

KE = 4 J

The maximum particle velocity occurs when PE = 0 and KE = ME

The lowest particle velocity occurs when KE = 0 and PE = ME

So  :

KE = ME

The position when the particle on the maximum speed (PE = 0) occurs when particles at x = 1 and x = 4

The kinetic energy of the vehicle

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law of motion  

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Keywords: kinetic energy, speed,particle,turning points, motion, work,  potential energy, mechanical energy

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