English

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’. Suma is swimming in a pond. - Science

Advertisements
Advertisements

Question

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

Suma is swimming in a pond.

One Line Answer

Solution

Suma is moving forward while swimming by applying force in a particular direction and is getting displaced in the direction of force hence, work is being done.

shaalaa.com
  Is there an error in this question or solution?
Chapter 11: Work and Energy - Exercises [Page 158]

APPEARS IN

NCERT Science [English] Class 9
Chapter 11 Work and Energy
Exercises | Q 1. 1 | Page 158

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?


In which of the following cases is work being done:

  1. A boy pushing a heavy rock
  2. A boy climbing up the stairs
  3. A coolie standing with a box on his head
  4. A girl moving on the road.

State two disadvantages of producing hydroelectricity.


When do we say that work is done? Write the formula for the work done by a body in moving up against gravity. Give the meaning of each symbol which occurs in it.


P, Q and R are three forces which act as shown in fig.

The point O lies in the same plane. Given, P = Q = R = 10N

(i) Which force has the least moment about O? Give a reason.

(ii)Which force has the greatest moment about O? Give a reason.


A uniform circular motion is an accelerated motion. Justify it.


Distinguish between work and power.


Complete the following sentences:

Kilowatt is the unit of ....... and kWh is the unit of


Complete the following sentences:
 Joule is the unit of .......


Define kinetic energy.

Name the physical quantity which is associated with the work done by a body.

A body of mass 2 kg is moving with a speed of 20 ms-1. What is its K.E.?

In what form is energy stored in a wrist watch?

Fill in the boxe to show the corresponding energy transformation.


State the energy changes which take place when An electric bulb glows when it is connected to a source of electric current.


A water pump raises 50 kg of water through a height of 25 m in 5s. Calculate the power supplied by the pump (Take: g = 10 N kg−1).


Work done by this force at any instant is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×