Work and Energy - Exercise

NCERT Exemplar Solutions Class 9 Science Solutions for Work and Energy - Exercise in Chapter 11 - Work and Energy

Question 19 Work and Energy - Exercise

A ball is dropped from a height of 10 m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back? (g = 10 m s–2).

Answer:

mgh=m×10×10= 100m joules

when 40% energy is reduced remaining energy will be 60mjoules

Hence 60 – m x 10 × h

H = -6m

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Exercises

Work and Energy - Exercise

Chapters

Matter in our Surroundings

Is Matter Around Us Pure ?

Atoms and Molecules

Structure of the Atom

The Fundamental Unit of Life

Tissues

Diversity in Living Organisms

Motion

Force and Laws of Motion

Gravitation

Work and Energy

Sound

Why Do We Fall ill ?

Natural Resources

Improvement in Food Resources