Question

A crowbar of length 3 cm is pivoted at a 15cm from its tip .

calculate :

a) mechanical advantage of the crowbar

b) least effort required at its other end to displace a load of 150 kgf.

❎no spams please ❎​

Answer 1

hey mate

here is your answer....

the question seems to be wrong as the Length of the crowbar cannot be less than load arm.

however, assuming the length of the crowbar to be 30cm

then,

a)-load arm =15 cm

effort arm=15 cm

thus,

it's MA=Ea/La

=15 cm/15 cm

=1 (answer)

b)-MA=1

load =150 kgf

therefore,

effort=load /Ma

=150 kgf (answer)

Answer 2

✴OLA!!✴

⤵⤵SOLUTION :⤵⤵

CROWBAR IS A LEVER OF 1ST ORDER .

GIVEN : TOTAL LENGTH OF CROWBAR = 3m = 300 cm

LOAD ARM OF CROWBAR = 15 cm

THEREFORE , EFFORT ARM OF CROWBAR = (300-15) cm = 285 cm

a) MECHANICAL ADVANTAGE = VELOCITY RATIO = EFFORT ARM/ LOAD ARM = 285 cm/ 15cm = 19.

b) TAKING MOMENT ABOUT PIVOT

EFFORT*EFFORT ARM = LOAD* LOAD ARM

=>E*EFFORT ARM = LOAD*LOAD ARM

E*285cm = 150kgf * 15cm

E= (150kgf*15cm )/285cm = 7.89 kgf ANSWER✔✔✔

TYSM❤❤