Blog #5

Solar panels make sense for a primary usable energy source because we will always have the sun unless it is night time, all day long while the sun is shinning on the solar panels it is creating energy. Different temperatures during the day, creating heat(energy) apply the 2nd law of thermodynamics. The changing of temperatures will cause a form of energy to be created.



1. Sally does 210J of work lifting herself 5.5 m with a gravity pull of 9.8
What is Sally's mass?

Us=(1/2)kx^2
x=5.5
Us=?
F=210

(210)(5.5)= 1155


2. What is the definition of Us?

(a)the energy stored in a compressed or stretched spring
(b)the energy of motion for an object
(c)a measure of stiffness of a spring

answer: a

3.  What is the variable, definition and unit of power?
-variable: P
-definition: the rate at which energy is used
-unit: Watts(w)