Question

Mechanic can open a note by applying a force of 150 Newton while using a lever handle of length 40 cm how long handle is required if you wants to open it by applying a force of only 50 Newton

Answer 1

Torque for case 1 :

Torque = Force × Perpendicular distance from axis of rotation

T1 = 150 N × 0.4 m

T1 = 60 Nm

Torque for case 2 :

T2 = 50N × Length of handle

So Torque 1 and Torque 2 should be same

So Torque 1 and Torque 2 should be sameequating we get

T1 = T2

60 = 50 × L

60 / 50 = L

6/5 = L

1.2 m = L

Ans : Length of handle should be 1.2m

Hope the solution is clear to you!!