Advertisements
Advertisements
प्रश्न
A pair of nut crackers is 12 cm long. An effort of 10 gf is required to crack a nut which is passed at a point 3 cm from the finger. Calculate the load Fig.
उत्तर
Let L be the load.
Given, load arm = 3 cm
effort arm = 12 cm
Effort, E = 10 gf
Now, M.A = `"effort arm"/"load arm" = 12/3` = 4
Also MA = `"L"/"E"`
4 = `"L"/10`
or, L = 40 gf
APPEARS IN
संबंधित प्रश्न
A gear system has the driving wheel of radius 2 cm and driven wheel of radius 20 cm.
(a) Find the gear ratio.
(b) If the number of rotations made per minute by the driving wheel is 100, find the number of rotations per minute made by the driven wheel.
(c) If the driven wheel has 40 teeth, find the number of teeth in the driving wheel.
A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0s. It lifts a load of 75.0 kgf. Calculate the power input to the pulley taking the force of gravity on 1 kg as 10 N.
In a block and tackle system consisting of 3 pulleys, a load of 75 kgf is raised with an effort of 25 kgf. Find:
- the mechanical advantage,
- velocity ratio and
- efficiency.
A block and tackle system has 5 pulleys. If an effort 0f 1000 N is needed in the downward direction to raise a load of 4500 N, calculate:
- the mechanical advantage
- the velocity ratio, and
- the efficiency of the system.
A block and tackle system has the velocity ratio 3. Draw a labelled diagram of the system indicating the points of application and the directions of load L and effort E. A man can exert a pull of 200 kgf. What is the maximum load he can raise with this pulley system is its efficiency is 60%?
Complete the following sentences:
1 J = ........ Erg.
A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0 s. It lifts a load of 75.0 kgf. Calculate : the height to which the load is raised in 4.0 s.
A machine is driven by a 50 kg mass falling at a rate of 10.0 m in 5s. It lifts n load of 250 kgf. Taking the force of gravity on 1 kg mass as 10 N. Calculate the power input to the machine. If the efficiency of the machine is 60%, find the height to which the load is raised in 5s.
The mechanical advantage of a machine is 5 and its efficiency is 80%. It is used to lift a load of 200 kgf to a height of 20 m. Calculate:
(i) The effort required, and
(ii) The work done on the machine (g = 10 ms−2).