Physics Circle home Student Login

Home›Chapters›Laws of Motion PYQs›Equilibrium, Third Law & Frames›Question 12

MHT CET 2022 (11 Aug, Shift 2) · Equilibrium, Third Law & Frames

Equilibrium, Third Law & Frames question from MHT CET 2022 (11 Aug, Shift 2)

Q12MHT CET 2022 · 11 AUG · SHIFT 2Easy

Equilibrium, Third Law & Frames

A door 1.2 m1.2\text{ m} wide requires a force of 1 N1\text{ N} to be applied perpendicular at the free end to open or close it. The perpendicular force required at a point 0.2 m0.2\text{ m} distant from the hinges for opening or closing the door is

Show answer and solution

Answer: (d)

  1. The torque about the hinge must be the same: F1r1=F2r2F_1 r_1 = F_2 r_2.
  2. 1×1.2=F×0.21 \times 1.2 = F \times 0.2
  3. F=6 NF = 6\text{ N}
  4. So the answer is (d) 6.0 N.
Report a mistake

More questions on Equilibrium, Third Law & Frames