Ch 3 Physics Class 11

• Very Important Multiple Choice Questions (MCQs) with Answers of the Ch 3 Physics Class 11 in Physics Class 11 Sindh Book Boards.
• Definition of Displacement with diagram
• Definition of Velocity with diagram and Explanation
• Velocity From Distance – Time Graph
• Definition of Acceleration with explanation
• Acceleration From Velocity – Time Graph
• Equations of Uniformly Accelerated Rectilinear Motion
• Newton’s laws of motion:  Newton’s First Law of Motion
• Define Inertia
• Explain Newton’s Second Law of Motion
• Explain Newton’s Third Law of Motion
• Define and Explain Tension: (i) When both objective move vertically (ii) When one object moves vertically and other moves on a horizontal surface.
• Define and Explain Momentum
• State and Explain Law of Conservation of Momentum
• Definition of elastic collision
• Definition of inelastic collision and elastic collision in One dimension
• Definition of force of friction with explanation and coefficient of friction Merits and Demerits of Friction
  
• Definition of the force of friction with explanation and coefficient of friction
• Merits and Demerits of Friction
• Fluid Friction & Viscosity
• Fluid Friction or Viscous Drag
• Definition of inclined plane with explanation
• In an electron gun of a television set, an electron with an initial speed of 103 m/s enters region where it is electrically accelerated. It emerges out of this region after 1 micro second with speed of 4x105 m/s. What is the maximum length of the electron gun? Calculate the acceleration. 
• A car is waiting at a traffic signal and when it turns green, the car stats ahead with a constant acceleration of 2 m/s2 . At the same time a bus traveling with a constant speed of 10 m/s overtakes and passes the car. (a) How far beyond its starting point will the car overtake the bus? (b) How fast will the car be moving?
• A helicopter ascending at a rate of 12 m/s. At a height of 80m above the ground, a package is dropped. How long does the package take to reach the ground?
• A boy throws a ball upward from the top of a cliff with a speed of 14.7 m/s. On the way down it just misses the thrower and fall the ground 49 metres below. Find (a) How long the ball rises? (b) How high it goes? (c) How long it is in air and (d) with what velocity it strikes the ground.
• A helicopter weighs 3920 Newton. Calculate the force on it if it is ascending up at a rate of 2 m/s 2 . What will be force on helicopter if it is moving up with the constant speed of 4 m/s? 
• A bullet having a mass of 0.005 kg is moving with a speed of 100 m/s. It penetrates into a bag of sand and is brought to rest after moving 25cm into the bag. Find the deceleration force on the bullet. Also calculate the time in which it is brought to rest.
• A car weighing 9800 N is moving with a speed of 40 km/h. On the application of the brakes it comes to rest after traveling a distance of 50 metres. Calculate the average retarding force. 
• An electron in a vacuum tube starting from rest is uniformly accelerated by an electric field so that it has a speed 6x106 m/s after covering a distance of 1.8cm. Find the force acting on the electron. Take the mass of electron as 9.1x10-31 kg.
• Two bodies A & B are attached to the ends of a string which passes over a pulley, so that the two bodies hang vertically. If the mass of the body A is 4.8 kg. Find the mass of body B which moves down with an acceleration of 0.2 m/s2 . The value of g can be taken as 9.8 m/s2. 
• Two bodies of masses 10.2 kg & 4.5 kg are attached to the ends of a string which passes over a pulley in such a way that the body of mass 10.2 kg lies on a smooth surface and the other body hangs vertically. Find the acceleration of the bodies and tension of the string and also the force, which the surface exerts, on the body of mass 10.2 kg.
• A 100 grams bullet is fired from a 10 kg gun with a speed of 1000 m/s. What is the speed of recoil of the gun?
• A 50 grams bullet is fired into a 10 kg block that is suspended by a long cord so that it can swing as a pendulum. If the block is displaced so that its centre of gravity rises by 10cm, what was the speed of the bullet?
• A machine gun fires 10 bullets per second into a target. Each bullet weighs 20 gm and had a speed of 1500 m/s. Find the force necessary to hold the gun in position. 
• A cyclist is going up a slope of 30o with a speed of 3.5 m/s. If he stops pedaling, how much distance will he move before coming to rest? (Assume the friction to be negligible). 
• A body starts from rest and moves with constant acceleration of 10 m/s2.How much distance will it travel in the 4th second of its motion?
• A brick of mass 2 kg is dropped from a height of 5m above the ground. What is its velocity at a height of 3m above the ground?
• A balloon tied up with a wooden piece is moving upward with velocity of 15 m/s.At a height of 300 m above the ground, the wooden piece is detached from the balloon. How much time will it take to reach the ground?
• A stone if dropped from the peak of a hill. It covers a distance of 30 meters in the last second of its motion. Find the height of the peak.  
• A car is waiting at a traffic signal. As it turns green, the car starts ahead with a constant acceleration of 3 m/s2.At the same time, a bus travelling with a constant speed of 20 m/s overtakes and passes the car. (a) How far beyond the starting point will the car overtake the bus? (b) What will be the velocity of the car at that time?