Question

Arrange the examples in order, starting with the object that has the least amount of energy. In each case, assume there’s no friction. Use g = 9.8 m/s2, PE = m × g × h, and .
Tiles
a book with a mass
of 0.75 kilograms
resting on a shelf at a
height of 1.5 metersa brick with a mass of
2.5 kilograms falling
with a velocity of
10 meters/second
when it’s 4 meters
above grounda ball with a mass of
0.25 kilograms rolling
on flat ground with a
velocity of
10 meters/seconda stone with a mass
of 0.7 kilograms being
held still at a height of
7 meters

Answer 1

The answer is the 1-1, 2-4,3-2,4-3... hope it helps and yall understand these.. :)

Answer 2

Answer: a book with a mass  of 0.75 kilograms  resting on a shelf at a  height of 1.5 meters<  a ball with a mass of   0.25 kilograms rolling  on flat ground with a  velocity of  10 meters/second< a stone with a mass  of 0.7 kilograms being  held still at a height of  7 meters< a mass of  2.5 kilograms falling  with a velocity of  10 meters/second  when it’s 4 meters  above ground

Explanation: Gravitational potential energy is the energy possessed by an object due to its position or height.Kinetic energy is the energy possessed by an object by virtue of its motion.

$P.E=m\times g\times h$

m= mass of object

g= gravity

h= height of an object

$K.E=\frac{1}{2}\times mv^2$

v= velocity of object

$(1kgm^2s^{-2}=1Joule)$

A) a book with a mass  of 0.75 kilograms  resting on a shelf at a  height of 1.5 meters

$P.E=0.75kg\times 9.8ms^{-2}\times 1.5m=11.025J$

B)  a mass of  2.5 kilograms falling  with a velocity of  10 meters/second  when it’s 4 meters  above ground

$K.E=\frac{1}{2}\times mv^2$

$K.E=\frac{1}{2}\times 2.5kg\times (10)^2=125J$

$P.E=m\times g\times h$

$P.E=2.5\times 9.8\times 4=98J$

total energy= (K.E+P.E) =(125+98) =223J

C) a ball with a mass of   0.25 kilograms rolling  on flat ground with a  velocity of  10 meters/second

$K.E=\frac{1}{2}\times mv^2$

$K.E=\frac{1}{2}\times 0.25\times (10m/s)^2=12.5J$

D) a stone with a mass  of 0.7 kilograms being  held still at a height of  7 meters

$P.E=0.7kg\times 9.8ms^{-2}\times 7m=48.02J$