What is the relationship between potential energy and kinetic energy?

Question

is the potential energy of a block on top of a slope equal to the kinetic energy of the block when it reaches the bottom of the slope?

Answer 1

Change in KE = Change in PE

Answer 2

E(total)=E(potantial)+E(kinetic)

in this case of an inclined plane E(p)=E(K) or

mg h = m v^2 /2

.

Answer 3

These people above know what they are saying.  E(potential) is closest. The key is to realize that energy is always conserved. We can write that

E(total) = E(kinetic) + E(potential) + E(work done against friction) + E (air resistance)

Notice that E(total) - constant

On the very top

E(total) = E(potential)  Since the body has not statrted to slide

E(kinetic) =0

E(work done against friction) =0

E (air resistance)=0

On the very bottom  E(potential)=0

E(total) = E(kinetic) + E(work done against friction) + E (air resistance)

By assuming an ideal system where

E(work done against friction) =0

E (air resistance)=0  

As potential energy diminishes it gets converted to kinetic energy.

Answer 4

In the absence of friction and air resistance, the KE at the bottom of the slope will be equal to the change in PE from top to bottom of the slope.

Answer 5

Yes it is.  The forumla for ke is 1/2*mass*velocity*.  And pe is mass*gravity*height.   ke+pe=total energy and the amount of total energy is always the same and since the block is at the bottom, the height is at 0 meaning there's no potential energy because anything times 0 is 0, therefore at the bottom it's all kenetic energy.  When it was at top and not moving, velocity was 0 thus 0 ke meaning it was all pe.  

Answer 6

In case there is no friction between the block and the plane, the  potential energy of the block on top of the slope is equal to the kinetic energy of the block when it reaches the bottom of the slope