Short Answer TypeState the energy changes in the following devices while in use:
i) A loud speaker
ii) A glowing electric bulb
A man having a box on his head, climbs up a slope and another man having an identical box walks the same distance on a levelled road.? What does more work against the force of gravity and why?
A body is thrown vertically upwards. Its velocity keeps on decreasing. What happens to its kinetic energy as its velocity becomes zero.
Two forces each of 5 N act vertically upwards and downwards respectively on the the two ends of a uniform metre rule which is placed at its mid-point as shown in the diagram. Determine the magnitude of the resultant moment of these forces about the mid-point?
Draw a diagram to show how a single pulley can be used so as to have its ideal M.A. = 2
Derive a relationship between mechanical advantages, velocity ratio and efficiency of a machine.
Let a machine overcome a load L by the application of an effort E.
In time t, let the displacement of effort be dE and the displacement of the load be dL.
Work input = Effort × displacement of effort
= E × dE
Work output = Load × Displacement of load
= L × dL 
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