Q. 17

Rashmi was playing on a swing in a park. To increase her speed when her swing was at its lowest position during its oscillations she pushed the ground hard with her feet. She enjoyed it but could not understand the mechanism. Her elder brother Pankaj explained her the reason, when she asked him.

(i) What type of energy was possessed by Rashmi while swinging? On what factors does it depend?

(ii) Why did the swing’s speed increase on pushing the ground harder with feet?

(iii) Why and what did Rashmi ask Pankaj?

Answer :

(i) At the extreme position of the swing she will have potential energy. At the mean position of the swing, she will have kinetic energy. These energies keep interchanging during the motion of the swing.

The kinetic energy depends on the velocity of the mass so it will be greatest at the bottom and, zero at the top. The gravitational potential energy depends on the height. It will be maximum at the top of the swing and minimum at the bottom.


(ii) On pushing ground harder with the feet, force is applied on the swing. As a result of it the swing starts moving with the greater speed and the speed of the swing increases.


(iii) Rashmi asked her brother pankaj that why on pushing the ground with the feet the speed of the swing increases. She asked so because she is curious to know that why the speed of the oscillations was increasing on pushing the ground when at the lowest position.


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Quiz | Lets Solve NumericalsQuiz | Lets Solve NumericalsQuiz | Lets Solve Numericals54 mins
Let's Calculate Workdone by a BodyLet's Calculate Workdone by a BodyLet's Calculate Workdone by a Body42 mins
Smart Revision | Let's Understand PowerSmart Revision | Let's Understand PowerSmart Revision | Let's Understand Power40 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
NCERT | Introduction to WorkNCERT | Introduction to WorkNCERT | Introduction to Work39 mins
Lakhmir Singh | Work, Energy and PowerLakhmir Singh | Work, Energy and PowerLakhmir Singh | Work, Energy and Power38 mins
Smart Revision | Let us Calculate the EnergySmart Revision | Let us Calculate the EnergySmart Revision | Let us Calculate the Energy53 mins
Smart Revision | Master Work and Its ConceptsSmart Revision | Master Work and Its ConceptsSmart Revision | Master Work and Its Concepts47 mins
Quiz | Lets Solve the NumericalsQuiz | Lets Solve the NumericalsQuiz | Lets Solve the Numericals57 mins
Rapid Fire QuizRapid Fire QuizRapid Fire Quiz53 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