Download App

Work and Energy — Science STD 9 — Question

Maharashtra BoardEnglish MediumSTD 9ScienceWork and Energy3 Marks
Question
Give one example each in which a force does (a) positive work (b) negative work, and (c) zero work.
✓

Answer

  1. Positive work: Work done by the force applied by a person on a ball that is thrown upwards.
  2. Negative work: Work done by gravitational force of earth on a ball thrown upwards.
  3. Zero work: Work done by gravitational force of earth on a box that is sliding horizontally on the ground.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Question Answer (3 Marks)" from Work and Energy→Work and Energy — all question types→Science STD 9 question papers→Maharashtra Board STD 9 question papers→Maharashtra Board question paper generator→

Similar questions

The mass of sun is $2 \times 10^{30}\  kg$ and the mass of earth is $6 \times 10^{24}\ kg$. If the average distance between the sun and the earth be $1.5 \times 10^8\  km$, calculate the force of gravitation between them.
→
How many moles of oxygen atoms are present in one mole of the following compounds?
  1. $Al_2O_3$
  2. $CO_2$
  3. $Cl_2O_7$
  4. $H_2SO_4$
  5. $Al_2(SO_4)_3$
→
State three reasons why you think air is a mixture and water is a compound.
→
Describe a method for separating a mixture of iron filings and sulphur powder other than that by using a magnet.
→
Calculate the density of an object of volume $3m^3$ and mass $9\ kg$. State wheater this object will float or sink in water. Give reason for your answer.
→
Name the energy transfers which occur when:
  1. An electric bell rings.
  2. Someone speaks into a microphone.
  3. There is a picture on a television screen.
  4. A torch is on.
→
Find the momentum of a body of mass 100g having a kinetic energy of 20J.
→
What is the range of frequencies associated with (a) infrasound (b) audible sound, and (c) ultrasound?
→
What is the number of zinc atoms in a piece of zinc weighing $10\ g$?
(Atomic mass of $Zn = 65\ u$)
→
Why does the temperature remain constant during the boiling of water even though heat is supplied continuously?
→