Advertisements
Advertisements
प्रश्न
A girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a levelled road. The work done against the gravitational force will be (g = 10 m s–2)
पर्याय
6 ×103 J
6 J
0.6 J
zero
Advertisements
उत्तर
zero
Explanation:
The gravitational force on the bag, i.e. the weight of the bag is in a vertically downward direction whereas the distance moved by her is in the horizontal direction. It means that the force and displacement are perpendicular to each other, therefore no work is done.
APPEARS IN
संबंधित प्रश्न
State whether the object possess kinetic energy, potential energy, or both :
A ceiling fan in the off position ______________
What kind of energy is possessed by the following?
A stone kept on roof-top _______________
What is the difference between potential energy and kinetic energy?
An iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass 3.5 kg. Both the spheres are dropped simultaneously from a tower. When they are 10 m above the ground, they have the same :
Name the device or machine which convert :
Heat energy into kinetic energy (or mechanical energy).
Name the device or machine which convert :
Chemical energy into heat energy.
The hanging bob of a simple pendulum is displaced to one extreme position B and then released. It swings towards centre position A and then to the other extreme position C. In which position does the bob have :
(i) maximum potential energy?
(ii) maximum kinetic energy?
What do you understand by the term 'transformation of energy"? Explain with an example.
How much electric energy in kWh is consumed by an electrical appliance of 1000 watts when it is switched on for 60 minutes?
When an object falls freely towards the earth, then its total energy :
