Q. 803.9( 10 Votes )

A bullet of mass 15 g has a speed of 400 m/s. What is its kinetic energy? If the bullet strikes a thick target and is brought to rest in 2 cm, calculate the average net force acting on the bullet. What happens to the kinetic energy originally in the bullet?

Answer :

Given,

Mass = 15g = 0.015kg,


Initial velocity = 400m/s,


Distance, s = 2cm = 0.02m


K.E. (initial) = 1/2mv2


= 1/2 x 0.015 x (400)2


K.E. (initial) = 1200J


As final velocity = 0.


Therefore, K.E. (final) = 0 (Where F is the average force)


F = 1200/2 × 10−2


= - 6 × 104 N


Negative sign shows that force is acting opposite to the direction of motion of the bullet. And the kinetic energy originally in the bullet is eventually transformed into heat energy by friction.


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
Quiz | Lets Solve NumericalsQuiz | Lets Solve NumericalsQuiz | Lets Solve Numericals54 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
Smart Revision | Master Work and Its ConceptsSmart Revision | Master Work and Its ConceptsSmart Revision | Master Work and Its Concepts47 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
NCERT | Energy and Its TypeNCERT | Energy and Its TypeNCERT | Energy and Its Type45 mins
Foundation | Rapid Fire QuizFoundation | Rapid Fire QuizFoundation | Rapid Fire Quiz36 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