Advertisements
Advertisements
Question
A 4 m long rod of negligible weight is to be balanced about a point 125 cm from one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm.
- If a weight W is placed at a distance of 250 cm from the support on the longer arm to balance the rod, find W.
- If a weight 5 kgf is kept to balance the rod, find its position.
- To which class of lever does it belong?
Advertisements
Solution
(a) W × CE = 18 × DC
W × 250 = 18 × 60

∴ W = `(18 xx 60)/250`
∴ W = 4.32 kgf
(b) New W = 5 kgf
Let it be placed at a distance x from C on arm CB
∴ 5 × x = 18 × 60
∴ x = `(18 xx 60)/5`
= 216 cm
(c) It belongs to class I lever.
APPEARS IN
RELATED QUESTIONS
The diagram below shows a lever in use:

- To which class of levers does it belong?
- Without changing the dimensions of the lever, if the load is shifted towards the fulcrum what happens to the mechanical advantage of the lever?
Draw a diagram of a lever which is always used as a force multiplier. How is the effort arm related to the load arm in such a lever?
Fig 3.17 below shows a lever in use.

(a) To which class of lever does it belong?
(b) If FA = 80 cm, AB = 20 cm, find its mechanical advantage.
(c) Calculate the value of E.
Which type of levers have mechanical advantage always more than 1? Give reasons.
Give three examples for leavers of second order.
Which class of lever found in the human body is being used by a boy when he raises the weight of his body on his toes?
The following belong to which class of lever?
A claw-hammer
The following belong to which class of lever?
A pair of scissors
Shears, used for cutting metals and scissors used for cutting clothes are both examples of levers of the first order. However, whereas the shears always have short blades and long handles, the scissors often have blades much longer than the handles. Explain, why this is so?
The following are an example of levers. State the class of lever to which each one belongs giving the relative positions of Load (L), Effort (E), Fulcrum (F):
(i) Scissors (ii) Sugar tongs (iii) Nutcracker (iv) Pliers.
