One cubic meter of water is poured off a 100-m high bridge. if the change in gravitational potential energy is converted into electricity with an efficiency of 90%, how long can this energy illuminate a standard 60-w light bulb?

the light bulb can be illuminated 14700 sec (= 245 minutes or 4 hours and 5 minutes)

Step-by-step explanation:

the change in gravitational potential energy ΔE is

ΔE= m*g*h = ρ*V*g*h = 1000 kg/m³ * 1 m³ *9.8 m/s² * 100 m = 980000 J

where

ρ= density of water

V= volume of water

g= gravity

h= height

the energy required to illuminate a light bulb is

e*ΔE = P*t

where

P= power required by the lightbulb

t= time

e= efficiency

then

t =  e*ΔE/P = 0.9 * 980000 J / 60 W = 14700 sec (= 245 minutes or 4 hours and 5 minutes)

linear pair postulates

when rotating a figure 180 degrees, imagine that you are able to take the figure and turn it clockwise or counterclockwise around a center point. to rotate a figure 180 degrees, you will need to apply the rule (x, y) → (-x, -y). start by using a coordinate grid with coordinates for each vertex of the figure. the center point of the coordinate grid is located at (0, 0), which is what you will rotate the figure around. write down the original coordinates of the shape you are going to rotate. then, apply the rule. for example, coordinate (1, 2) becomes (-1, -2). another example would be, coordinate (-4, -2) becoming (4, 2). after you change each original coordinate to the rotated coordinate, you will draw your new figure.

step-by-step explanation: