21. Physics Grade 11th First Semester Final Exam The system shown below is in equilibrium. What are the value of tension T, and T2 respectively? A. 200N,20N B. 0,200N T C. 100N, 100N D. 50, 150N 200N What is the work done by a force which is at 90° to the displacement of an object? A. F.S B. O C.-F.S D. 1J A 20g bullet travelling at 400m/s embeds itself in sand bag. What is the impulse of the bullet's force on the sand bag? A. 800N.S B. 8NS C. BONS D. 4NS A 3kg trolley moving at 4m/s collides with and joins to a stationary trolley of mass 2kg on a horizontal frictionless surface. What is the speed at which the trolleys move after ཞ ཉ ན ་ ། ་ ན ་ འ ད collision? A. 1m/s B. 3.5m/s C. 2.4m/s D. 6m/s Which of the following is not a characteristics of Newton's pairs of action and reaction forces A. Equal in magnitude B. Opposite in direction C Act on different bodies D. Act on the same bodies Two force of equal magnitude 10N is acting on an object of mass 5kg. The angle between the forces is 90°. What is the magnitude of the acceleration of the object? B.10m/s² c. 2√2 m/s² D. 20m/s² A. 5√2 m/s² D. Conduction Which of the following is the transfer of heat by the movement of a particle? A. Radiation B. Convection C. Insulation 28. The direct transfer of heat from one substance to another substance that is touching is reffered to as A Convection 29. 30. B. Radiation C. Conduction D. Insulation What is the term that describes the flow of energy from hot body to a colder body? C. Conduction B. Sound A. Convection D. Heat A door made of iron has length of 2m at 20°C. If the temperature increases to 25°C. what change of length of the door? (The coefficient of linear expansion of iron ​