Advertisements
Advertisements
प्रश्न
उत्तर
Moment of force = applied force x perpendicular distance from the pivot
= 10 x 30 x 10 -2
= 3 Nm
APPEARS IN
संबंधित प्रश्न
The S.I. unit of energy is .............
No work is done by a force if the body
Define work.
State two factors on which the work done on a body depends.
Define the term energy.
A boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1.
In case of negative work, the angle between the force and displacement is :
What is meant by a translational motion? Give one example.
Name the force acting away from the centre of circular path.
What is the work done when the object acted upon by a force remains at rest?
A man lifts a mass of 10 kg from the floor to a shelf 4 meter high. If g = 10 ms-2, what is the work done?
Write an expression for the work done against gravity.
(a) Define power and name its unit.
(b) A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
Fill in the boxe to show the corresponding energy transformation.
State the energy changes which take place when A stone dropped from the top of a cliff reaches the ground after some time.
How long should an electric motor, of power 2 H.P. operate, so as to pump 5 m3 of water from a depth of 15m. [Take g = 10 N kg−1]
A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.