JEE 2020 Physics: Laws of Motion Quiz 4 (24.07.2019)

A block A with mass 100 kg is resting on another block B of mass 200 kg. As shown in figure a horizontal rope tied to a wall holds it. The coefficient of friction between A and B is 0.2 while coefficient of friction between B and the ground is 0.3. The minimum required force F to start moving B will be

The displacement-time (x-t) graph of a body is given as



The corresponding velocity-time (v-t) graph will be

A body of mass m=10⁻² kg is moving in a medium and experiences a frictional force F=−kv². Its initial speed is v₀=10 ms^-1. If after 10 s its energy is . Find the value of k

A box of mass 2 kg is placed on the roof of a car. The box would remain stationary until the car attains a maximum acceleration. Coefficient of static friction between the box and the roof of the car is 0.2 and g = 10 ms^–2.
This maximum acceleration of the car, for the box to remain stationary, is

In the arrangement shown, the pulleys are fixed and ideal, the strings are light, m₁ > m₂ and S is a spring balance which is itself massless. The reading of S (in units of mass) is-

In the given arrangement, n number of equal masses are connected by strings of negligible masses. The tension in the string connected to n^th mass is–