Here, you will be provided with 10 solved practice questions from the chapter Work, Energy and Power. JEE Main is the preliminary stage of JEE. candidates who qualify JEE Main become eligible to give JEE Advanced. If you are preparing for JEE Main 2018, then you must practice these 10 solved questions based on Work, Energy and Power.
This test covers work done by a force, kinetic Energy, potential Energy and Work-Energy Theorem.
Q1. A bus can be stopped by applying a retarding force F when it is moving with speed v on a level road. The distance covered by it before coming to rest is s. If the load of the bus increases by 50% because of passengers, for the same speed and same retarding force, the distance covered by the bus to come to rest shall be
(a) 1.5 s (b) 2 s
(c) 1 s (d) 2.5 s
Q2. Power supplied to a particle of mass 2 kg varies with time as P = 3t2/2 W. Here t is in second. If the velocity of particle at t = 0 is v = 0, the velocity of particle at time t = 2 s will be
Q3. The kinetic energy K of a particle moving along a circle of radius R depends upon the distance s as K = as2. The force acting on the particle is
Q4. A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration ac, is varying with time t as ac = k2 rt2 , where k is a constant. The power delivered to the particle by the forces acting on it is
(a) Zero (b) mk2r2t2
(c) mk2r2t (d) mk2rt
Q5. A uniform chain AB of mass m and length 1 is placed with one end A at the highest point of a hemisphere of radius R. Referring to the top of the hemisphere as the datum level, the potential energy of the chain is
Q7. A block attached to a spring, pulled by a constant horizontal force, is kept on a smooth surface as shown in the given figure. Initially, the spring is in the natural length state. Then the maximum positive work that the applied force F can do is (given that string does not break)