What is the difference in PE between a 82.5 kg adult on a
1.25 m wall, and a 14.7 kg child
on the same wall?
(Unit = J)
HELP ME

831.4 J

Explanation:

Info given:

mass adult: 82.5kg

mass child: 14.7kg

height of wall: 1.25m

g = 9.81m/s^2

PE = mgh

For adult:

mgh = (82.5kg)(9.81m/s^2)(1.25m) = 1011.65 J

For child:

mgh = (14.7kg)(9.81m/s^2)(1.25m) = 180.25 J

Difference in PE: 1011.65 J - 180.25 J = 831.4 J

not moving. pos accel,

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form