Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 1]PhysicsNewton's Laws of Motion

A small block B is positioned on another block A of mass 5 kg and length 20 cm . Initially, block B is situated near the right end of block A , as shown in the figure. A constant horizontal force of 10 N is applied to block A . Assuming all surfaces to be frictionless, calculate the time elapsed before block B separates from block A .

Options

  1. A0.45 s
  2. B0.20 s
  3. C0.32 s
  4. D0.63 s

Correct answer

A. 0.45 s

Step-by-step solution

Since all surfaces are frictionless, there is no horizontal force acting on block B . Therefore, the acceleration of block B is zero ( a_B = 0 ). The horizontal force F = 10 N acts only on block A . The acceleration of block A is given by: a_A = F m_A = 10 5 = 2 m/s ^2 The relative acceleration of block B with respect to block A is: a_ rel = |a_B - a_A| = |0 - 2| = 2 m/s ^2 Block B is initially at the right end of block A . To separate from block A , it must cover a relative distance equal to the length of block A

Practice Newton's Laws of Motion on Quantrex Academy →

More from Newton's Laws of Motion

A block with a mass of 2 kg rests on a long frictionless horizontal table and is pulled horizontally by a constant force F . The block is observed to travel 10 m during the first tA block of mass 0.2 kg is suspended from the ceiling by a light string. A second block of mass 0.3 kg is suspended from the first block through another string. Determine the tensioPlaced on a smooth horizontal table, two blocks of equal mass m are connected by a light string. A constant force F is applied to pull one of the blocks along the line connecting tIn a TV picture tube, electrons are emitted from the cathode with negligible speed and attain a velocity of 5 10⁶ m/s after travelling one centimeter. Assuming straight line motionTravelling at 40 km/h , a car must be brought to a halt by applying brakes within the next 4.0 m . Given that the car weighs 2000 kg , determine the average force that must be applA particle of mass 50 g travels along a straight line. The variation of its speed with time is displayed in the figure. Determine the force acting on the particle at t = 2 , 4 , anTwo blocks A and B having masses m_A and m_B respectively are placed in contact on a frictionless table. An experimenter pushes block A from behind, causing the blocks to acceleratRaindrops, each having a radius of 1 mm and a mass of 4 mg , are falling at a speed of 30 m/s onto the head of a bald person. Upon splashing on the head, the drops come to rest. As Full Newton's Laws of Motion list All Concepts Of Physics MCQ Edition [Volume 1] PYQs