Question

In a simple axle and wheel, the diameter of the wheel is 180 mm and that of axle 30 mm. If the efficiency of the machine is 80%, find the effort required to lift a load of 100 N.​

Answer 1

Answer:

25 cm

d2 = 10 cm

Load W = 750 N

Efficiency η = 42 % = 0.42

Effort P=70 N

Velocity ratio VR

=

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

=

Distancemovedbyload

Distancemovedbyeffort

�

�

=

2

�

�

1

−

�

2

=

2

�

25

−

10

=

2

�

15

=

0.1333

�

VR=

d

1

−d

2

2D

=

25−10

2D

=

15

2D

=0.1333D

Mechanical advantage

�

�

=

�

�

�

�

�

�

�

�

�

�

MA=

Effort

Load

�

�

=

�

�

=

750

70

=

10.714

MA=

P

W

=

70

750

=10.714

Efficiency

�

=

�

�

�

�

η=

VR

MA

0.42

=

10.714

0.1333

�

0.42

×

0.1333

�

=

10.714

�

=

10.714

0.055986

=

191.37

�

�

0.42=

0.1333D

10.714

0.42×0.1333D=10.714

D=

0.055986

10.714

=191.37cm