Q. 104.1( 127 Votes )

An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when it is half way down (g = 10 m/s2)

Answer :

Given,

Mass, m = 40 kg


Acceleration due to gravity, g = 10 m/s2


Height, h = 5 m


We know that,


Potential energy = m × g × h


= 40 × 10 × 5


= 2000 J


When the object is fall to its half way down, then its height above the ground =


=2.5 m


Now, Potential energy = m × g × h


= 40 × 10 × 2.55 J


= 1000 J


Now, we know that according to the law of conservation of energy:


Total potential energy = Potential energy at half way down + Kinetic energy at half way down


2000 = 1000 + Kinetic energy at half way down


Kinetic energy at half way down = 2000 – 1000


= 1000 J


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Let's Calculate Workdone by a BodyLet's Calculate Workdone by a BodyLet's Calculate Workdone by a Body42 mins
Foundation | Let us Understand Law of Conservation of EnergyFoundation | Let us Understand Law of Conservation of EnergyFoundation | Let us Understand Law of Conservation of Energy44 mins
Introduction to WorkIntroduction to WorkIntroduction to Work40 mins
Foundation | Rapid Fire QuizFoundation | Rapid Fire QuizFoundation | Rapid Fire Quiz36 mins
Conservation of Mass-EnergyConservation of Mass-EnergyConservation of Mass-Energy41 mins
How Does Barometer Work?How Does Barometer Work?How Does Barometer Work?36 mins
Cell Organelles of Energy MetabolismCell Organelles of Energy MetabolismCell Organelles of Energy Metabolism49 mins
Champ Quiz |  2-Dimension( Coordinate geometry )Champ Quiz |  2-Dimension( Coordinate geometry )Champ Quiz | 2-Dimension( Coordinate geometry )36 mins
Matter and Its ClassificationMatter and Its ClassificationMatter and Its Classification34 mins
Speed and VelocitySpeed and VelocitySpeed and Velocity59 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :