Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET2015PhysicsLaws of MotionActual

A rod of weight W is supported by two parallel knife edges A and B and is in equilibrium in a horizontal position. The knives are at a distance d from each other. The centre of mass of the rod is at distance x from A . the normal reaction on A is:

Options

  1. AW x d
  2. BW d x
  3. CW d - x x
  4. DW d - x d

Correct answer

D. W d - x d

Step-by-step solution

Equation for force balance N A + N B = W ...(i) N B = W - N A Equation for torque balance about centre of mass of rod. N A x = N B d - x N A x = W - N A d - x N A x = W d - W x - N A d + N A x N A d = W d - x N A = W d - x d

Practice Laws of Motion on Quantrex Academy →

More from Laws of Motion

The magnitude and direction of the acceleration produced in a body of mass 5 kg when two mutually perpendicular forces 8 N and 6 N act on it, are respectively : 2026A box of mass 15 kg is kept on the floor of a stationary trolley. The coefficient of static friction between the box and the trolley is 0.12 . Keeping the box in stationary state o 2026A car travels on a circular racetrack of radius 50 m, which is banked at an angle . If the car travels at a speed 10 ms ⁻¹ , then the wear and tear on its tyres is minimum. Taking 2026There are two inclined surface of equal length (L) and same angle of inclination 45^ with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2025A uniform rod of mass 20 kg and length 5 m leans against a smooth vertical wall making an angle of 60^ with it. The other end rests on a rough horizontal floor. The friction force 2025A box of mass 5 kg is pulled by a cord, up along a frictionless plane inclined at 30^ with the horizontal. The tension in the cord is 30 N . The acceleration of the box is (Take g= 2024A bob is whirled in a horizontal circle by means of a string at an initial speed of 10 rpm. If the tension in the string is quadrupled while keeping the radius constant, the new sp 2024A horizontal force 10 N is applied to a block A as shown in figure. The mass of blocks A and B are 2 kg and 3 kg respectively. The blocks slide over a frictionless surface. The for 2024 Full Laws of Motion list All NEET PYQs