Free help with homework

Why join Brainly?

  • ask questions about your assignment
  • get answers with explanations
  • find similar questions

NCERT CLASS IX - Science Textbook

Chapter 11 - Work and Energy

The kinetic energy of an object of mass, mmoving with a velocity of 5 m s - '1is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?



This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Velocity = v = 5 m/s
mass = m

Kinetic energy = 1/2 m v² 
  1/2 m * 5² = 25 Joules
  =>   m = 2 kg

When the velocity v is doubled,  since there is  v²  in the expression for KE.,  KE becomes 2² = 4 times.
   So  the KE will be 25 J * 4 = 100 Joules.

when the velocity is increased to 3 times its original value:  ie., 15 m/sec,  its KE is 3² = 9 times ,  hence,  9 * 25 J = 225 Joules.

1 5 1
please click on thanks blue button above
The Brain
  • The Brain
  • Helper
Not sure about the answer?
Learn more with Brainly!
Having trouble with your homework?
Get free help!
  • 80% of questions are answered in under 10 minutes
  • Answers come with explanations, so that you can learn
  • Answer quality is ensured by our experts