People

often

wonder

about

the

weight

of

Balanced

Rock

at

Arches

National

Park

in

the

United

States.

Perched

on

a

pillar

of

rock,

Balanced

Rock

is

estimated

to

weigh

about

three

million

kilograms.

Geologists

could

not

actually

weigh

the

rock,

so

they

estimated

its

weight.

They

took

a

sample

of

the

rock

and

measured

and

weighed

it.

Then

they

multiplied

that

weight

by

the

total

size

of

the

rock

to

get

the

estimated

weight.