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If the suitcase falls off the cupboard, it will lose its potential energy. Halfway down the cupboard, the suitcase will have lost half its potential energy and will have only 9,8 J left. At the bottom of the cupboard the suitcase will have lost all it's potential energy and it's potential energy will be equal to zero.

Objects have maximum potential energy at a maximum height and will lose their potential energy as they fall.

A brick with a mass of 1 kg is lifted to the top of a 4 m high roof. It slips off the roof and falls to the ground. Calculate the potential energy of the brick at the top of the roof and on the ground once it has fallen.

    • The mass of the brick is m = 1 kg
    • The height lifted is h = 4 m

    All quantities are in SI units.

    • We are asked to find the gain in potential energy of the brick as it is lifted onto the roof.
    • We also need to calculate the potential energy once the brick is on the ground again.
  1. Since the block is being lifted we are dealing with gravitational potential energy. To work out P E , we need to know the mass of the object and the height lifted. As both of these are given, we just substitute them into the equation for P E .

  2. P E = m g h = ( 1 ) ( 9 , 8 ) ( 4 ) = 39 , 2 J

Gravitational potential energy

  1. Describe the relationship between an object's gravitational potential energy and its:
    1. mass and
    2. height above a reference point.
  2. A boy, of mass 30 kg , climbs onto the roof of a garage. The roof is 2,5 m from the ground. He now jumps off the roof and lands on the ground.
    1. How much potential energy has the boy gained by climbing on the roof?
    2. The boy now jumps down. What is the potential energy of the boy when he is 1 m from the ground?
    3. What is the potential energy of the boy when he lands on the ground?
  3. A hiker walks up a mountain, 800 m above sea level, to spend the night at the top in the first overnight hut. The second day he walks to the second overnight hut, 500 m above sea level. The third day he returns to his starting point, 200 m above sea level.
    1. What is the potential energy of the hiker at the first hut (relative to sea level)?
    2. How much potential energy has the hiker lost during the second day?
    3. How much potential energy did the hiker have when he started his journey (relative to sea level)?
    4. How much potential energy did the hiker have at the end of his journey?

Kinetic energy

Kinetic Energy

Kinetic energy is the energy an object has due to its motion.

Kinetic energy is the energy an object has because of its motion. This means that any moving object has kinetic energy. The faster it moves, the more kinetic energy it has. Kinetic energy ( K E ) is therefore dependent on the velocity of the object. The mass of the object also plays a role. A truck of 2 000 kg , moving at 100 km · hr - 1 , will have more kinetic energy than a car of 500 kg , also moving at 100 km · hr - 1 . Kinetic energy is defined as:

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Maths test. OpenStax CNX. Feb 09, 2011 Download for free at http://cnx.org/content/col11236/1.2
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