हिंदी

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’. A donkey is carrying a load on its back. - Science

Advertisements
Advertisements

प्रश्न

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

A donkey is carrying a load on its back.

लघु उत्तरीय

उत्तर

  • While carrying a load, the donkey has to apply a force in the upward direction. But the displacement of the load is in the forward direction.
  • Since displacement is perpendicular to force, the work done is zero.
shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 11: Work and Energy - Exercises [पृष्ठ १५८]

APPEARS IN

एनसीईआरटी Science [English] Class 9
अध्याय 11 Work and Energy
Exercises | Q 1. 2 | पृष्ठ १५८

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

A coolie does no work against the force of gravity while carrying a luggage on a road.


Work done by a boy depends on the time in which he does work.


Work is said to be done by a forte only when ................


The S.I. unit of energy is .............


Write the expression for work done by a force.


What are the two kinds of mechanical energy?


Give reasons for the following A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work.


A body of mass 5 kg falls from a height of 10 m to 4 m. Calculate:

The loss in potential energy of the body, 


A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?


Write the formula for work done on a body when the body moves at an angle to the direction of force. Give the meaning of each symbol used.


The work done on an object does not depend on the :


What is the relationship between Nm and dyne cm?


A weight lifted a load of 200 kgf to a height of 2.5 m in 5 s. calculate: (i) the work done, and (ii) the power developed by him. Take g= 10 N kg-1.


A block of iron of mass 400 kg is used as a pile driver. If it is raised to a height of 20 meters, calculate the potential energy possessed by the iron block. (Assume g= 10 ms-2).

Fill in the boxe to show the corresponding energy transformation.


Give an example 
Chemical energy changes to heat energy.


Is power a scalar or a vector quantity?


Name the material commonly used for the manufacturing of solar cells.


What is power? How do you differentiate kilowatt from kilowatt-hour? The Jog Falls in Karnataka state are nearly 20 m high. 2000 tonnes of waterfalls from it in a minute. Calculate the equivalent power if all this energy can be utilized? (g = 10 m s–2)


A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×