Difference between Potential and Kinetic Energy - Essay Example

A good example is when two objects collide (collision theory). In this case, a stationary body can obtain kinetic energy from moving. On the contrary, potential energy is not transferable to other bodies, but it can be converted to kinetic energy.

A good example of kinetic energy is the moving water at a waterfall while potential energy is when the energy possessed by water at the brim of the waterfall before it precipices.
Q3
In such case, the total kinetic energy of the block is converted to potential energy gain in the spring:
That is, KE (block) = PE (spring)

KE (block) = ½ x mass x squared velocity [1/2mv2]…………………………………………….. (i)
=1/2 x 4 x 25
=50 Joules
PE (spring) = ½ x constant (stiffness) x squared extension/ compression ………………………….. (ii)

= ½ x2500 N/m x e2 where e gives the extension/compression.
= 1250e2 joules

Since KE (block) = PE (spring), we shall equate (I) and (II)
That is,
1250e2 joules = 5000 Joules and hence e2 = 50/1250 = 0.04 and hence e = 0.04 = 0.2 meters.

Q3: analysis
13:
Potential energy is directly connected with forces. If the work done on a body by a force that moves from point A to B is independent of the path between the two points, then the work done by this force is assigned a scalar value on each point in space and is referred to as a scalar potential field. This means that the integral equation drawn from the line representing the change of force between these two points can be defined as the negative of the vector gradient and it gives the potential field. This potential field is the equivalent of the change in potential energy between the two points.

That is Potential Energy U=-φ(x)
This explains why the spring’s potential energy is given as a negative value. The negative sign denotes the convection that works done by a force field increases the PE while work applied against the force field reduces the potential energy
14:
It is important to note that work is required to either reduce or increase the potential energy of a body. In this case, a change in potential energy principally reflects the work done on the object. Therefore, the integral derivative of a PE function will give the amount of work done. Again the value is given as a negative figure to denote that the work done has reduced the PE possession of the body.

Conclusion
1. A normal pendulum with a few modifications can be used to achieve similar objectives. In this case, a zero position for the pendulum is identified. Since many labs are done on tabletops, the table top is assigned to the zero height (mean) position. If the tabletop is designated the zero position, then the PE of an object is dependent on its relative height from the tabletop. Therefore, by obtaining the mass of the pendulum and its relative height from the tabletop, the gravitational potential energy can be calculated following:
PE = mass x relative height x Gravitational pull
= mg
2. As a car goes over a rough road or bumps, the spring in its shock-absorber setup is compressed, but the potential energy of the elastic spring immediately brings it back to a position of equilibrium. This ensures that the bump is not distributed throughout the vehicle. In this case, the energy accumulated as a result of the bumpy surface is consumed in compressing the spring.