The amount of gravitational potential energy acquired by the rock is equal to:

where
m is the mass of the rock
g is the gravitational acceleration

is the increase in height of the rock
Substituting the data of the problem, we find

So, Natalie gave 220.7 J of energy to the rock.
They tend to be lustrous, ductile, malleable, and good conductors of electricity, while nonmetals are generally brittle (for solid nonmetals), lack lustre, and are insulators. Use google.
Answer:
554.27N
Explanation:
(a) The max frictional force exerted horizontally on the crate and the floor is,
Substitute the values,
μs=0.5
mass=113kg
g=9.81m/s
Ff=μsN
=μsmg
=(0.5 x 113 x 9.81)
Ff=554.27N
Answer:
400 kilogram
Explanation:
Force exerted is directly proportional to the mass of an object.
F=ma where m is mass and a is acceleration. Taking uniform acceleration on all objects then the larger the mass the higher the force and vice versa. Theredore, among the masses given, 400 kilograms is the largest hence it exerts the largest force at the bottom
The answer should be 2times3.14 which equals 6.28