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प्रश्न
An electric motor pump is 60% efficient and is rated 2.5 H.P. Calculate the maximum load it can lift through a height of 10m in 8 sec. (1 H.P. = 750 W).
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उत्तर
Useful power supplied by the motor =`(2.5xx750 xx60)/100` watt
= 1125 watt
If maximum load lifted is W kg, then :
Work done in lifting up the load = W × 10 × 10 J
And Work done by the pump = 1125 × 8
Or Load lifted; W =`(1125xx8)/(10xx10)` = 90 kg.
संबंधित 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 sailboat is moving due to wind energy.
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
Fill in the blank with suitable word :
Work is measured as a product of __________ and __________
Define the term 'work'. Write the formula for the work done on a body when a force acts on the body in the direction of its displacement. Give the meaning of each symbol which occurs in the formula.
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
(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.
A canon ball of mass 500g is fired with a speed of 15m/s-1. Find: its momentum.
Define Translational motion.
If a ball is dropped on the sloping roof of a house, it acquires ______ and falls on the ground. That is the transformation of ______ energy into ______ energy takes place.
(kinetic, potential, motion)
