Physics
Three levers X, Y, Z of equal lengths are shown in the diagram.

(a) Which class of lever do these belong to?
(b) Among these (X, Y or Z) which one will give the maximum mechanical advantage? Justify your answer.
Related Questions
(a) Name the radiations :
- for which a quartz prism is used to study the spectrum.
- which are used in remote sensing devices.
- which are used in traffic signals in India.
(b) Name one property common to all electromagnetic radiations.
Akash takes a uniform metre scale and suspends a weight of 2 N at one end ‘X’, and a weight of 5 N on the other end ‘Y”. He then balances the ruler horizontally on a knife edge placed at 70 cm from X. Draw a diagram of the arrangement and calculate the weight of the ruler.
Richa weighing 40 kgf leaves point P on her skateboard and reaches point Q on the ground with velocity 10 ms-1. Calculate.

(a) the kinetic energy of Richa at point Q
(b) the vertical height of point P above the ground. (use g as 10 m/s2 and neglect friction)
(c) the kinetic energy of Richa at point R. (While moving from Q to R, she loses 500 J of energy against friction.)
Draw a block and tackle system of pulleys with velocity ratio equal to 3.