II. Energy (Joules) - 2 kinds

 

 

 

 

Potential & Kinetic Energy

 



A) Potential Energy - stored energy that an object has due to its position or condition.

At what position(s) or condition(s)
do these objects have the most PE?

1. Gravitational P.E.g

(PE = Potential Energy)

 

P.E.g= (mg) h =  (weight) h 
Joules Kg (m/s2)m N m
    (Not in reference)

 

g on earth = 9.8 m/s2

mg = weight - force it could exert

h = height - distance force could be exerted

 

 

ΔP.E. = mgΔh = wΔh
    (Not in reference)

 

Ex 1) What P.E. is gained when a 100. kg object is raised 4.00 m straight up?

 

Ex 1) What P.E. is gained when a 100. kg object is raised 4.00 m straight up?

m = 100. kg
h = 4.00 m

 

ΔP.E. = mgΔh

= (100. kg)(9.81 m/s2)4.00 m

 

= 3920 J

 

 

Ex 2) What PE would be gained if an object were moved 4 m to the right?

 

 

ΔP.E. = 0

 

 

Ex 3) An object weighing 15. N is lifted from the ground to a height of 0.22 m. Find object's change in PE

 

 

 

Ex 3) An object weighing 15. N is lifted from the ground to a height of 0.22 m. Find object's change in PE

 

 

ΔP.E. = mgΔh = wΔh
    (Not in reference)

 

w = 15. N

h = .22 m

 

 

ΔP.E. = wΔh

 

ΔP.E. = 15. N(.22m)

 

ΔP.E. = 3.3 Nm