Physics-DPP-2-law of motion

PHYSICS Topic: LAWS OF MOTION Date: 1. An elevator and its load have a total mass of 800 kg. If the elevator, originally moving downward at 10 m/s, is brought to rest with constant deceleration in a distance of 25 m, the tension in the supporting cable will be : (g = 10 m/s2) : (a) 8000 N (b) 6400 N (c) 12200 N (d) 9600 N 2. A block of weight 5 N is pushed against a vertical wall by a force 12 N. The coefficient of friction between the wall and block is 0.6. The magnitude of the force exerted by the wall on the block is : (a) 12 N (b) 5 N (c) 7.2 N (d) 13 N 3. The acceleration of the 2 kg block, if the free end of string is pulled with a force of 20 N as shown is : (a) zero (b) 10 m/s2 (c) 5 m/s2 (d) 6 m/s2 4. Two blocks, each having a mass M, rest on frictionless surfaces as shown in the figure. If the pulleys are light and frictionless, and M on the incline is allowed to move down, then the tension in the string will be : (a) 2 Mg sin θ 3 (b) 3 Mgsinθ 2 (c) Mg sin θ 2 (d) 2 Mg sin θ 5. In the shown figure the tension in the upper string immediately after lower string is cut is (a) mg (b) 2 mg (c) 3 mg (d) 3 mg 2 6. In the 5th question the acceleration (in m/s2) of block A & B just after lower string is cut are (a) 0,g ¯ (b) g ­ g ¯ (c) g ¯ g ¯ (d) g ­ g ­ PHYSICS Topic: LAWS OF MOTION Date: 7. A smooth inclined plane of length L, having an inclination θ with horizontal is inside a lift which is moving down with retardation a. The time taken by a block to slide down the inclined plane from rest will be : (a) (b) (c) (d) 8. Three blocks are placed at rest on a smooth inclined plane with force acting on m1 parallel to the inclined plane. Find the contact froce betweem m2 and m3. (a) (m1 + m2 + m3 )F (b) m3F (c) F – (m + m )g (d) None of the above m1 + m2 + m3 1 2 3 9. In this figure how much force on mass m = 5kg should be applied, so that it just won’t slip. Given that car is moving with constant acceleration a = 5 m/s2. (a) 170 N (b) 180 N (c) 150 N (d) 250 N 10. All surfaces shown in figure are smooth. System is released with the spring unstretched. In equilibrium, compression in the spring will be : mg (a) (b) 2mg k (c) (M + m)g mg (d) k PHYSICS Topic: LAWS OF MOTION Date: Answer Key 1. (d) 2. (d) 3. (b) 4. (c) 5. (c) 6. (b) 7. (d) 8. (b) 9. (c) 10. (d)

Comments

Popular posts from this blog

Planning to start your own coaching institute for JEE, NEET, CBSE or Foundation? Here's why not to waste time in developing study material from scratch. Instead use the readymade study material to stay focused on quality of teaching as quality of teaching is the primary job in coaching profession while study material is secondary one. Quality of teaching determines results of your coaching that decides success & future of your coaching while good quality study material is merely a necessary teaching aid that supplements your teaching (video in Hindi)

Physics-30.24-Physics-Solids and Semiconductors

Physics-31.Rotational Mechanics