Advertisements
Advertisements
प्रश्न
उत्तर
Given mass m = 1000 kg
velocity v = 72 km/hr = 20 m/s
Now K.E = `1/2` mv2 = `1/2` (1000)(20)2
or,K.E = 2 x 105 J
APPEARS IN
संबंधित प्रश्न
When does a force perform work?
A body, when acted upon by a force of 10 kgf, moves to a distance 0.5 m in the direction of force. Find the work done by the force. Take 1 kgf = 10 N.
Express joule in terms of erg.
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
Define 1 joule of work.
A car is being driven by a force of 2.5 ✕ 1010 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.
A force of 50 N acts on a body and moves it a distance of 4 m on horizontal surface. Calculate the work done if the direction of force is at an angle of 60° to the horizontal surface.
Choose one or more correct alternatives.
For work to be performed, energy must be ______.
- transferred from one place to another
- concentrated
- transformed from one type to another
- destroyed
Nm is the unit of .......
A machine raises a load of 750 N through a height of 16 m in 5s. calculate:
(i) work done by machine,
(ii) power at which the machine works.
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
Give an example
Electrical energy changes to heat energy.
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
What are the advantages and disadvantages of using solar cells for producing electricity?
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A wind-mill is lifting water from a well.
